Have you ever owned a car that keeps you up at night? one that needs so much work you don't even know where to begin? Or one that has so many weird problems that you start dreaming of the diagnostic steps to figure them out only to have those dreams turned into nightmares and you wake up in a pool of your own sweat with no answers whatsoever. Have you have you? Yeah, Me neither. I'm just kidding. of course my CL65 AMG has been nothing short of a nightmare since day one now.

I Bought this car knowing it was leaking engine oil and hydraulic suspension oil and after an insane ride home from Kansas where we almost died from freezing to death I removed the engine. The oil issue is a one dollar o-ring that required the heads to come off. so I went a little nuts while I was in there replacing everything and installing larger hybrid turbos, ported cylinder heads, and much much more. And everything was looking great until I found a hole in a coolant jacket where they ported too far.

So I had that welded up, reassembled and installed the engine and on first start a fuel injector stuck open and it hydrol locked. These injectors were totally fine before and I only needed them to drive to the dyno before the tune, but that's my luck with this car. I replaced the fuel injectors and we were good again. The engine was running great, but then the hydraulic suspension that just had a cut and dry leaking pump which I replaced with the engine out took me down a path.

I don't wish upon anyone very long story short, an accumulator ball exploded and sent rubber throughout the entire system and I spent like three videos or about two months of my life figuring this out, cleaning lines and replacing everything. Now after that we were good. I even did some preliminary runs on the dyno with the stock. tune in.

The car ran well Craig from Modern Masters zipped in a new tomb file for all the mods and then this happened. The car would almost immediately fall on its face as soon as boost kicked in. So I learned that when you turn these up especially with bigger turbos, you can get spark blowout so that's where I'm at and I'm sure whatever I do will be super easy and the car won't give me any trouble at all. One last test before I burned this car to the ground.

All right ladies and gentlemen, we're ripping out the old Alex Mercedes-Benz shirt for this one. See this is the shirt that I used to wear at the dealer when I was a technician and I think once I started putting this on is when the CL65 started to really come together. So this is my my lucky shirt and I haven't even washed it since the last time I worked on this I'm I think I'm never gonna wash it all right. let's get into the CL65 engine yet again, try and fix it and finally finish this.

car. And I could come up with a bunch of excuses as to why I haven't worked on this but I'm not going to do that guys. The truth is I've just been I've been scared of the car I've had a lot of other projects and every time I think about working on this one. I'm like if I work on it and it's running again, something else might break and I don't want to deal with that so it's just taken me a little bit of time to build up the courage to get back in here.

But let's get right into this. Clear the mess. I'm feeling good I think the CL is going to be back better than ever and realistically all the hard stuff is already done. What's left is kind of fun gravy work.

Okay, there we go There she is. There's the beautiful M275. Wait a minute. Okay, that's not a good start that fell off.

Let's get right to wrenching. So I believe that the issue with this CL65 is a spark blowout issue. So we're going to start off by re-gapping the spark plug. So typically if you increase the Boost level, you want to tighten up the gap on the spark plugs.

otherwise the Boost will literally blow it out. kind of like a candle. So right now I'm just removing these Red Rubber boots that go inside of the ignition coil and often get stuck on the spark plug. I've removed all of the red boots and these are practically new from when I did all the engine work so they don't really need to be replaced.

But my new rebuilt coils that I'll show you guys in a moment have new red boots so we're just going to go with these. and I Can't wait to show you this! Let's remove spark Plug number one out of 24. Yep This has two plugs per cylinder 12 cylinders. So if my Chicago public School education serves me right, that's 24..

very expensive and parts alone to do this tune-up Okay I Took my actual spark plug socket on one of our little road trip adventures and lost it. So dealing with a magnet here to get these plugs out, here we go. Let's check the Gap So here's our very expensive CL65 spark plug. Um, and these are Ruthenium Plugs by NGK They're a very good plug, but one issue.

you can't get these. They're very explicit on their website that you can't touch the Gap but in speaking with my friends at V12 Icpac.com who made my coils, they said they've gapped like hundreds or maybe thousands of these without any issues. So we're going to go ahead and replace all the spark plugs. if we take a look at the Ruthenium spark plug.

see this little extension right there? This guy doesn't have it. It's more of a traditional spark plug and I wonder if there's an issue with that becoming fragile once you start gapping? Now there's many ways to Gap a spark plug. A lot of people will just take it and kind of Beat It on the table or the ground until this closes up a little. Uh, not the best way to do it, especially when there's options like this.

This was I think maybe 25 or something like that on. Amazon I'll drop you a link down below, but this is a spark plug gapper and it's much more gentle on the plug. You just place it in like that and then we're going to gently screw this until it's tight. Okay, so now we're just holding the plug firm.

You can definitely use one of these gappers you get at the spark plug store. but I Really like using an actual feeler gauge set and we're going to go for 24 thousands for the gap on this plug. It comes pre-gapped at twenty eight thousand, so we're just tightening it up a little bit. And yeah, right now it's super loose in there.

So we'll do is we'll keep the feeler in there and we'll tighten it just a little and then let out. That's your true Gap Yep, there it is, so we can definitely feel a little bit of drag, but we've closed it up just a tad. If you want to double check, go to the original Gap and see if that'll fit in there. Nope, Yeah, it won't fit in.

so we've closed it up. This plug is gapped and 23 more to go. Okay, but hang on before. I Take these spark plugs to Gapple Bees I Gotta show you guys this really cool battery slash alternator slash charger tester.

It's amazing. It's called the Top Done BT 300p Very simple to use. It's going to connect these right here so you're going to pick which kind of battery you have hold cranking amps. This is 910 and let's test.

Cool Good Charge 78 Health It gives you all this information and check this out. You can print it out So neat. You can get these right on Amazon I'm Gonna Leave a link down below and how you guys can save big money. but check this out.

Want to know if your starter is bad? Sure no problem. Crank Test Please start engine and it's giving us a normal reading. Everything's good with that and now you can do a charging test. Also wants us to increase the RPM to 2500 we're going to press enter testing again Charge normal.

Look at this thing's good. Top Down has a battery tester for any budget so with this one you can print it comes with a really nice case. It'll do 12 volt and 24 volts. so you can use this testing.

a boat and RV a car truck whatever you'd like and then this one does all of that as well. You just don't get a case and it won't print and then this little guy is a more basic tester. but it'll still do all three tests as well. So don't pay anyone one hour of Labor to diagnose your car.

You can buy one of these tools for a lot less than that and you can use it over and over and over again. It's super easy. Click on the Amazon links down below. Let's get back to some V12 action.

All right. I got my iced coffee. Should we play here while I do this? You know what? I'm going to see Blink 182. hey Google Shuffle songs by Blink 182.

all right. here's a blue fan or not. I can't bring you with for this part I'll get copyright. Clinical Small things all right.

23 spark plugs are gapped ready to go I saved the last one to show you guys what I've learned fumbling around with this thing every time. time is kind of annoying. So I just removed the two feeler gauges that I needed and the reason I needed two I Realized this went much quicker when I just went with a 20 000. So I put the twenty thousandths in there, tightened it up until that was in there nice and snug.

That's it. You really can't go anymore and that way we would actually get about twenty four thousands. Yeah, it's perfect. There's a little bit of spring back here, so when you just use the twenty four thousandths, it's still kind of loose.

It's more like 26 000 or 27 000 something like that. So I use that thinner feeler gauge and then when it springed back, it would actually be closer to twenty four thousands. All right, that's my 24th plug. Let's get all these old ones out here.

We go 23 spark plugs to remove and then 24 to install. It's a little time consuming I'm not gonna lie, but we got Tunes we got Tunes people I could go more Blink 182 Actually, by the time you guys see this video I would have already gone and I'm going or I went with a couple people you may recognize from my videos. Hopefully we had a good time. All right I'm gonna rock out to some Taking Back Sunday and I know I'm kind of dating myself I listen to a lot of like 90s 2000s What? What is Blink 182 in a band like that is that Emo? is that punk I don't know what kind of what kind of genre of music is that even called? Anyway, I'm into everything.

we're probably gonna do a little NOS after that, maybe a little. Darius Rucker I'm a big fan of Darius Rucker here I am taking a picture in front of his house in Charleston I Had to Anyway, let's do some spark plugs. Shuffle songs by Taking Back Sunday I Know exactly what goes on. All right.

One bank is out and I loosened up all of the passenger side. so now we can just use a magnet and pluck them out and then install our new gapped plugs. These plugs do look a little dark and that's most likely because I had to drive this car a bit on the stock tune with the larger fuel injector. so I was running a little rich and then a lot of short trips and idling because it's just kind of been sitting around here in the garage for the winter.

But anyway the engine was still running really well and I think these would have cleaned up. but that's neither here nor there because we have these now. Many modern spark plugs are coated. The threads are coated so you don't need anti-seize some spark plugs.

you still need some Nic So just double check with the manufacturer. They usually have it listed right on their site. You always want to start these by hand. You can zip them in with a gun on a very low setting after they've been started by hand, but don't risk cross threading.

Okay, and then after they become snug, you just need a little bit more. This style spark plug has a crush washer here and that's what makes the seal all right. This box is empty. That means all of our new spark plugs have been installed and it's time for our rebuilt coil pack.

So my issue here with this cutting out at wide open throttle because of more boost pressure and the more aggressive tune is likely a two-part issue. So the gap on the spark plugs that we just went over blowing out the spark like a candle and also weak coil pack. X So these gigantic, super expensive coil packs, they do wear out. So if you have over 60 or 70 000 miles and you start getting a misfire code, it'll start maybe with a PO 300, then 302, then 304 and it'll specify what cylinder you could have a portion of the coil pack that's faulty and these are not sold individually.

You just get one gigantic pack per bank, but you have options outside of going to the dealer and spending I think about fourteen hundred dollars per coil. It's it's insane. Instead, you can send your coils into V12cipac.com and you're going to get these for around half of what the dealer charges and their rebuilt in-house in the United States to be better than ever. So basically what happens is when these fail, you can either get a misfire and that's because they've worn out just over the years.

Heats High Resistance internally or in my case, it ran fine under normal conditions, but it just didn't have the umph to power up those spark plugs at wide open throttle. But what's cool is they just came out with this. It's called a boost box and it replaces the old voltage Transformer that sits right here on top of the engine and gets hot. And this guy is also going to help us diagnose when coil packs go bad, which is pretty cool.

So anyway, let's get the coils in. then we'll get the Boost box in. All right? So I've sprayed a little bit of silicone spray on the new rubber boots and then you just gotta shimmy these guys in. and just be careful.

they're kind of fragile. You definitely don't want to drop one of these things or anything. I Don't know which side is harder than the other I'm going to take this bolt out there. we go and you don't have to take the intercoolers off.

They have coolant in them so you'd have to bleed the entire system if you did, and you can just kind of get them up out of the way. That's just a little little. Shimmy Shake Because you're trying to line up 12 boots at the same time. push them down evenly.

Piece of cake. Plug this guy in. Click and we don't want to forget our ground. There we go.

Driver's side coil going back home. So these are my original coils. They're on a core Exchange program, but these are mine because I wrote on them. so I know.

Okay, sweet. with the coil packs bolted in, we can go ahead and reinstall our intake tube. so just leave the intercoolers loose for this part and then they just slide right over the turbos. and then you install this little horseshoe clamp and tighten the bolt down, Tighten up all the intercooler clamps and we are almost home free.

Now here's something that's super awesome. We get to get rid of this stupid bracket that broke all the rubber mounts break on these all the time. We are deleting this bracket delete weight reduction. Anyone with a V12 probably knows what I'm talking about, but these bushings to mount that voltage Transformer on this bracket, they always break.

Now we'll have to relocate that ground and we have a beautiful Factory option right here. This is kind of neat. I Was worried where we were going to put this boost pressure sensor. It normally mounts on a bracket that mounts to that big bracket, but with the hose connected, it sits here just perfectly, almost like they wanted us to mount it there.

The Boost box mounting is very easy. You just put it right in here. fits in here beautifully, so that's good. Oh, this is great.

Look at this. Factory Grommet right here. Open it up a little bit and there is definitely the perfect amount of room for this additional wiring harness. Slide it on through and then reinstall our Factory seal and this is an old Rentec lowering module that doesn't work anymore.

I Could totally just disconnect this, but I'm Gonna Leave it right there for Nostalgia Then we're just going to run the harness here. plug it into the factory connector like so and we'll just run a zip tie right about here. Turn good. Almost there.

We just have our air boxes to sneak in. and don't forget to plug in the two little sensors on each box like that air box number two going in. The only downside to getting rid of that Center bracket is that there are two mounting holes for the air box, but those basically haven't been connected for probably many, many years. I Still get one in the back and then the covers go right on top and it's super snug.

Even without those, the aftermarket intakes don't have anything that hold the boxes onto the turbos. It's kind of crazy. Before the Beauty covers, let's fire this up. Fire in the V12 hole.

ladies and gentlemen. Twin Turbo V12 With bigger turbos, ported cylinder heads, different blowout Bell Larger injectors. It's alive. Wow.

And is it smooth? That's that's what the B12 is about. Smooth as glass. This thing hasn't been started in a long time either. Cool.

Well, my gloves are ripped so you know we're almost done doing mechanical work here. We have a Dyno appointment tonight. Did I do this wrong? I Rebuilt this whole engine. Forget how to do the beauty cover.

It's carbon fiber. First there we go. Now we can go with this. And yes, I'm missing the little Mercedes star.

It's okay. this car does have aftermarket Mufflers but It's just very, very quiet. It's decent when you give it some throttle though. listen to this foreign by decent I Just don't think it's that loud.

But honestly I have so many loud cars that it's kind of nice having an ultra high performance car like this. that's kind of quiet. You guys want to see the worst cup holder? whatever. Mercedes I Don't know what they were thinking back in the day.

these things are ridiculous. Like it's It's honestly more dangerous than just just doing one of these. but I'm not gonna do that. so we'll just close this up just in case it falls.

I've let the CL idle for about a half hour. The gas is pretty old so I can't go wide open throttle yet I have to burn out this gas. luckily it's a V12 so that'll be in like an hour. What do you guys think of these Rivians? You like them I know they don't tow much I mean they tow a lot, but not for very long.

but 0 to 60 in three seconds. It is the nicest. Day Ever 75 and Sunny in Chicago I'm back in the CL it's running great I Can't go wide open throttle right now because I have your old gas in here. Check this out guys! Distronic Cruise Control: This is one of the first adaptive cruise control system on any car 2005.

slowing down for the guy ahead look I can set the cruise to 80. it won't go 80. unless you up on its own. All right.

Well, I'm pulling over I gave it like a half throttle. it kicked down. check engine light and it's running really bad. Uh, shut this off.

Okay, Yep. now it's running great. Check engine light's still going to be on. Yeah I got into a little boost but it was like half throttle.

Um, it could just be the really old gas I think it's over a year at this point. It kind of smells old. So okay. Don't go past a quarter throttle.

Definitely don't need it with this thing. All right. I've driven about 10 miles to let this gas kind of cycle through. Yeah, let's see.

let's see what happens. Basically I'm in first gear right now and once I get into any boost like half throttle. what it was doing is just completely cut now. I wouldn't do it that time.

That was nice. Let's do a little second gear. nothing yet. Okay that there it is.

Yep flashing check engine light. That's going to be misfire codes on a bunch of cylinders. like seven or eight of the 12 cylinders. Love misfires now.

Great yeah. the engine is shaking a little bit. It's definitely missing. Yep, lots of cylinder misfires all over the place.

All I have to do to temporarily fix this is shut the car off, fire it up again and it runs great. Just can't really get into boost and we need to get into boost it's twin turbo. V12 I Want to try a little experiment so the engine's pretty cold right now and every other time that I beat on this car like you're supposed to do I let the engine warm up, but for now I just want to see what happens if we beat on it cold. Is this temperature related? It might be.

See, we got Whoa. Okay, that ripped that ripped right off the bat. I let it warm up a little bit. There was a car in the way.

a semi truck actually. So we're gonna check temperatures right now and see see where we're at. but that man that pulled right off the bat like crazy. it hasn't done that yet ever since we've had this issue.

I had the engine off right now, but intake air temperature should be under 158 and I think this is happening as soon as it hits 150 degrees I think it's just totally shutting the car down and going into a limp mode that is very, very hot. especially considering we've only been running the engine for a few minutes. That's that's really bad. This is a split cooling system from the factory, which means it doesn't share the coolant for the intercooler system with the engine's coolant system.

So kind of like my E55 that does not have split cooling from the factory and that can make for higher intake. Air Temps this has that already. and the intercoolers being up top and fairly large, this should be a very robust system. This is no good.

Okay, check this out guys. I Waited for it to cool down to about 130 something and I'm going to hit it and we'll see if it shuts down right at 150 58. What's ripping? It's good. It's good.

It's good. It's good. Oh, and it's bad. So yeah, right now it's misfire and it totally shut down I have to pull over and reset this and I'll look back at the log.

but what are we at? Yeah, yeah, so it's like right around 147, probably 158 something like that. There's a bit of a delay with the feedback from the sensor, but it is shutting down immediately after it sees an intake air temperature that it doesn't like. This is a good thing guys. Now we can actually duplicate this concern consistently.

I'm gonna let it cool down one more time. We'll try it again, but we have to go after intake air temperature. We're going to hit this right at 150 and see if it cuts out right away. Yeah, so the sooner we hit it when it's closer to that 150-ish range, uh, it just immediately cuts out.

That is definitely what's going on that is way too high and what I think is happening because it's misfiring random cylinders I Don't know for sure. but back in the day with the Cadillac Northstar Engine they had an issue with overheating and the factory computer if it saw that the engine was overheating, it would shut the fuel to certain cylinders so the cylinders would draw in air and help cool the engine down so you could kind of limp home. And I think that's exactly what this car is doing I think it's shutting down these injectors because it thinks the intake air temperature is so high when you have that high of intake air temp, you could literally melt a Pistons So it seems like it's going into a massive safety feature mode and I'm just pulling into this random gas station. so I can shut it off because I don't like it misfiring like that.

But as soon as we start it back up, the intake air temperature is kind of settle down. Let's see where they're at now. yeah, like 143 and then they'll come down quite a bit in between hits. Okay, it's going up there.

we go yeah, 140 and we can get it down, but it doesn't last long and I'd imagine on a really hot summer day, it would just immediately fall on its face when you hit it if they start off around there. So let's go back to the shop and figure this out. We're getting somewhere this: V12 We'll live with all of its power and glory in this video. I Don't know why I say these types of things, but luckily there's a ton of wood in this car.

so I don't jinx myself I can knock on it. it's real wood. There we go. You're going to be fine.

Don't get too excited Alex This thing has disappointed me many, many times now. At this point I'm thinking this is one of two things. This could be clogged catalytic converters. That is a possibility that'll increase temperatures all over the place and make a car fall flat on its face.

So that's possible. Uh, and I'm going to show you guys no matter what if we fix this first a really cool back pressure tester so you could diagnose. if you have bad cats. We'll get to that.

But while the exhaust is blazing hot, we're going to tackle the intercooler system. and let me show you what I mean by the split cooling. So this is the coolant reservoir for the engine and that is where you fill up the coolant that runs through these intercoolers. You can see the pipes there and they have bleeders and whatnot.

and there's a large heat exchanger in the front and a pump down there and the pump could be our issue so let's take a look. Oh, and I just want to mention that I bled out the entire intercooler system and everything was working great when I did the engine like two years ago. We even had it on OJ's Dyno and that whole part of the system was fine, but we could have just simply had a failure. It happens, could be an old pump.

This pump could be the entire issue. Let's take it down. That's just one bolt. and I'm curious too the part number that would tell us about how old this thing is.

Yeah, there's a little sticker here. This thing is. it's crusty but shiny underneath. Let's take this little cap off and we'll slide the rubber sleeve up just a little.

Here we go. Now we can see that. full sticker. Yeah, this is an old pump.

It's from 2008. for Americans out there, they do this a little differently. This isn't from the future. It's not from 2025.

it's from 2008. that's a 15 year old pump. These things just really don't last that long. At the very least, this pump is probably really weak.

Let's see if it kicks on at all though. All right. So I have the charge air circulation pump that we can switch on so you hear the fans. Oh, there we go.

it's on. Yeah, I can definitely feel the pump kicking on that's for sure, but that doesn't mean it's a good pump and one way you can kind of tell is squeeze in the tubes that come out of it and you can feel the flow. This is going to be impossible for me to kind of show you, but it just feels like a tube with water in it. that's not flowing at all.

You should literally be able to feel it through the hoses. I Got nothing I Think this pump is just totally weak slash almost dead cool now. I Haven't installed the Vrp Whipple supercharger kit on my C63 AMG yet and I'm almost positive this comes with a pump that is just like the one on the CL Yep This is it by all the hoses and this should be an 010 Yeah, Oh yeah. I Went on right there and it's a little bit newer.

Yeah, this is going to be the exact same pump. Perfect. Awesome. This will fit all right.

So we're gonna borrow this from the C63 temporarily and uh, see what happens. All right, let's not lose all of the coolant in the system. We'll block it off with our little clamps. Here There we go and we'll remove our two hose clamps.

It's a really easy pump replacement. I'm gonna lose a little close clamp. Number Two Numero duet numero dos. What are some other ways to say Number two in different languages? comment down below.

Number Two in your language. Okay, I'm not gonna lie. Got a little coolant in my mouth. It's it's sweet.

It's tasty. It's shrinkable. If you want to die. Don't drink coolant.

It's bad. but it doesn't taste that bad. That's what makes it so dangerous. They say don't drink the Kool-Aid I Say don't drink the coolant.

All we need to do is switch over this sleeve right here. This just cuts down on vibration of this thing running. There we go. We'll dry it off a little bit, make it pretty, make it professional.

Get all these crusties off. Going back in new pump, give us our power back. Please Have you guys ever had a car like the CL Not not like exactly like the CL but a car that you've been working on for years and it just gives you problems? I Mean not that I'm working on this every day I Take many months off just to kind of mentally recuperate. but what? What do you guys have? What do you guys got? What do you drive that gives you problems like this? All right, that's good.

Clamp two going on. Beautiful hose clamp, click, look, release the fluid, release the fluid again. Ozone. Eventful.

I Was hoping for like a fluid releasing sound like oh so fluid. sounds like okay now back together with our clamp, our 10 millimeter going in okay, and our plug at the back and we're done. I'm just kidding, we're not done. We have to bleed this entire system.

There's going to be air in it now. It can be kind of a pain, but let me show you how to do it. Normally this requires like a two thousand dollar tool at Mercedes-Benz that I don't believe is available. Um, but let me show you guys another way to do it And it involves using organic low-fat milk.

One percent you got to use the one percent if you use the fat free milk. it doesn't have enough lubrication for the pump and you can burn it out. I'm just kidding I Just ran out of containers so I dug this out of the recycling bin and it's full of coolant. So anyway, uh, these tools are fantastic! I Just got this one from Harbor Freight I Used to use these a lot at the dealership, but they're really nice in creating a vacuum.

Tight Seal So we really didn't lose all that much coolant and it was bled before so we're now going to activate the pump. You know we'll put a little bit more in there just in case it sucks it down. If you do not have a computer to activate the pump, you can just put Power and ground. it's only a two wire connector there.

There's our fan kicking on so you can just activate it that way, turn the pump on and there we go. We got a couple bubbles. Initially, it's probably just a little bit of air we introduced. right now.

the pump is running okay now. I've turned the pump off and just one more step here because these can be a total nightmare to bleed out, especially if you're starting from scratch with a completely empty system but from the factory. The tools screws on here and it pushes these Schrader valves in. We don't have that, but that's okay.

we're gonna pull the Schrader valves out. This is the highest point in the system. You're going to lose a little. that's okay.

and then we're going to run this right back into itself and we'll do the same here with the other side. and we're going to take out the other Schrader valve on this intercooler. All right. I was there all right.

So we got both hoses right here and we're gonna activate the pump again. We should get some flow out of here. Yeah, so if you hadn't bled the system yet like like I did a while ago when I did the engine, uh, you would have air probably coming out and oh, we might have some. Look at that little reduced flow right there.

It might be fighting through a bubble right now and it might clear up here in a moment. Oh there we go. See that now it's shooting out a lot quicker. So yeah, we're gonna let this run for probably about five minutes.

Oh, there we go. Yeah, look at that. Yeah, right now it's just aerated so there's definitely air in the system. Hey, look at that.

Look at those bubbles. Suyo! So I have a battery charger hooked up because it runs the engine fan and this pump. You don't want to kill your battery, but we're going to keep this action going for a little while until I Feel that all the air is out of the system. Once you get your coolant out and it doesn't look frothy anymore, you can turn that off, stick that in your gallon of milk, and we'll back out of here.

So it turns off the fan and then this is a little stopper for our tool. Here we go and then we'll pop our Schrader valve back in. You're gonna get a little that comes out, no big deal and check this out. This is the coolest Schrader valve tool in the world so it's very easy to strip out Schrader valves and then sometimes you got to replace entire lines and get really expensive.

This is a torquing Fair valve tool I've had this for like over a decade I Have no idea where it's from or what brand. I'll find one. put a link down below but this is the way to go. If you over tighten these, it can cause a big headache and be very expensive.

Imagine this one is built into the intercooler so if you strip it out, you're getting a whole new intercooler. Okay, with our stopper in, we can just pull this up and not lose any fluid, put it back in our milk jug, and then this is a universal kit. so you get a few different adapters, you just get the one that fits your car. This is really common and there we go.

Totally filled, ready to rock. This is going to be our first start and you can see here charge. Air temperature sensor is reading 91 degrees Fahrenheit and it should be less than 95. This is at idle.

It will go down because we have airflow when you run the engine and we're going to keep an eye on this. Hopefully it stays within spec and I think when you're at wide open throttle it shouldn't go over 150. It really should never even come close to 150. That's way too high.

Let's go for a ride. Oh oh this feels good. Oh and it's oh man, these are fast. That's what I remember and this is still on the stock tune.

so I've reverted back to the stock tune. We had zipped in our performance tune file and just to eliminate anything I put the stock one in for all of these tests. so that's what we're on right now. let's let's do that again.

All right from a dig. here we go that yes oh man, these things are rocket ships and they're so smooth and like graceful when they do it. It's hilarious. It's quiet and it just shifts smooth and the whole car the ride it's it's a beautiful thing.

my CL65 you're alive. Okay so after all that we're at 111, that is awesome. I've switched it back to the wide open throttle. Live data you can see as soon as we get going get some airflow over the sensor.

It goes back down to normal. So it's summertime like I'd say anything like 10 20 degrees above ambient would be pretty normal and yeah, it's going right down cool. We were never able to do that before. that's a good sign.

All right. let's go wide open see where we're at. Foreign I've been driving for about 30 minutes and we are back up to 145 just sitting here. Oh man, that's what it was doing before.

All right guys, it's many hours later and uh, we have the same problem. So I got about five good blasts and like good all the way through second gear into third gear. felt great. Everything was looking okay uh and then at idle I Got back to the shop and it got up to like 150 and take care then 160 and it just will never ever recover.

but everything looks fine. I have spent the last few hours going over all of the hoses making sure the flow is in the right direction. The pump is working properly I believe I have it completely bled and it just won't work I'm on the phone with like two Master Certified Mercedes Friends of mine that I used to work with and they're kind of stumped as well I've tried everything. Now there is the factory bleeding tool but I've done this before without it I shouldn't absolutely need that.

They are a pain to bleed. but anyway I cracked this line right here with a pump on and I just just wanted to make sure we had flow going through everywhere and we do so I lost a little fluid on there I Popped the Y off because I want to run a little experiment where we just feel the air blowing out of each intercooler to see if one is cooler than the other. Maybe we can pinpoint one side? It's not working I don't know but I gotta do my quick bleed because I lost fluid This is by far the most disappointing and frustrating car that I've ever owned and tried to fix it. just fights me tooth and nail every single issue with this car.

It's just it never ends like you can't just fix it and it's like oh okay, that's it. It makes sense Like we had a bad coolant pump. Cool. Put a new coolant pump in.

we should be fine. Nope, we're not fine. All right. it's pretty aerated.

That's normal. I Had the line cracked, but man, this circuit seems complete. I mean pump is moving fluid. It's getting weak.

It's probably hitting a little air there. Yeah, and it gets strong. It gets through it. but yeah.

Typically when you have a completely dry system, you do want to put it into a vacuum and fill it like a normal radiator. But since I just swapped out the pump and we barely lost anything. so I Didn't Do It originally but I don't know. Nothing seems to make any sense.

This is really good flow. Okay, so here's my new setup. This is, uh, your normal coolant, radiator, bleeding tool. So we're gonna hook up shop air and then I Also have the schraders out.

These hoses are at the very bottom of this gallon that is totally filled. I've never done it this way. so let's see what happens. All right.

Pause action now. All right. So we're gonna get a little fluid that's totally normal and fine now. we have the pump on, see if it'll hold and it holds that.

five five inches and the face of the gauge is broken. Yes, I know, but it is going up now. I'm just gonna keep this going for a few minutes. According to Mercedes, you're supposed to hook up their tool and have it bleed for at least five minutes.

We're definitely not doing it exactly the way they do it, but it's kind of a similar concept without a two thousand dollar tool. Right now, we're using an empty gallon of chlorine and our organic milk stand here first. Okay, I've got everything back together except for the Y Let's start this thing up right now. We can feel air coming out of here from the turbochargers.

Not a whole lot, and the engine is just naturally aspirated at this point. Give it a little throttle, put some airflow. It's pretty cool right now, but we've been letting this thing sit around for a bit. I Just want to see if there's any difference at all.

So far, there's not. We'll keep this going. maybe if it's an issue with one side of the circuit. I Can pinpoint that, although like all the hoses are all connected, it's a very basic system with no thermostat.

there's just a pump, a heat exchanger and it flows cooling through there. And yeah, check for leaks. We vacuum bled. We've Alex bled.

Intake air temp is 130 right now with no intercooler action going into the engine. So far, this feels pretty cool, but we're really not giving it any load or anything like that, just kind of free revving. Here's where we're at after running for about 10 minutes. 154 intake air.

so that's really bad. This is the sensor by the way. I've pulled that out I've checked it. It's all good.

I replaced it when I did the engine and check this out. These are the pores the inside of the intercooler 105 and the other side is the exact same 105 and I'm kind of moving around this core. It's the same pretty much all the way around. and then with the air flowing, it feels good.

Let's see, with some air flowing, thank you! the air coming out of here should be about 10 degrees above Ambien Something like that. It's a really hot, muggy summer day, so I'm pretty happy with the air that's actually coming out of the intercoolers. I Don't know I'm at a loss, can't even talk. what else could this be? Now this is a new sensor when I did the engine I just broke a clip off of course.

but I want to see if we have this just sitting out here. What happens with the reading? Make sure this is working Okay, so I'll plug it right back in. Here's our charge air temp and it is definitely going down. not going down as fast as I'd like with this very very proper method of literally blowing on it.

Same there we go down to 125. it's still really hot in this area so I'm literally like blowing hot air on it. So even though it looks like our pump is Flowing a ton of fluid I Just want to double check the amperage draw. So this is an amp clamp.

very useful tool. I use this a lot when I worked for Mercedes we're checking for current draws, but you can use it for checking amperage draw on a component like a pump here. So we're doing is we're putting the clamp over the ground and you can see here we're pulling about 3.7 amps so we take it away, it goes away and we put it back and we have our 3.7 amps. Uh, that's probably spec I'm gonna see what information I can find, but that seems about right for a little pump like this.

We're gonna keep going with electrical tests right here. I Want to check the resistance of the intake air temperature sensor I Found some specs online and it looks like that at 20 degrees Celsius which is 68 degrees Fahrenheit we would be at 57.63 and then the top end of the Spectrum which I'm assuming would be 29 degrees Celsius is 63.70 currently in the shop where we're going to be right around 25 Celsius So split this right in half. Let's just say 6 000 Ohms is roughly what this should read. So all we're going to do is set up our multimeter to Ohms and then this is just a two pin sensor and let's see.

we got. Okay, Okay, so we're in Kilo Ohms so that's three point. Let's just say 3.5 so that's 3500 Ohms. That is way off.

Three thousandths would be way way way hotter. It's giving an OHM resistance reading for super hot which is the reading we're getting in the computer. This could be a bad sensor I'm not gonna lie I don't remember if I replace this I replaced a lot of everything when I had the engine apart I would have assumed I replaced this. There's a time stamp for 2020.

I think I did the engine in like 2021. so I did replace this. but that is not a good reading that is way way off. that's our Smoking Gun My screen needs a little oil and something's going on with my entire monitor system.

but we are taking the CTS-V to the Mercedes-Benz dealership to get a new intake air temperature sensor and I need I need new platelets or something Guys I cut my hand like yesterday and I thought it was done bleeding and now it's bleeding again. My platelets just aren't kicking in like they used to I don't know what's up with that I'm gonna diagnose that too. Mercedes-Benz We're definitely gonna do a pull with the CTS-V after we get this part and we'll check and compare intake air temperature because this is the same general system water to air. So I think this is probably a normal resting heartbeat kind of temperature for this car on a hot day.

but when we make a pull it'll go up and then it should come right back down to about this. That's not what the CL is doing. Can I just take the B12 engine out of that? That would fix a lot of my problems. Okay, you know I Can't wait to test this new part open! Okay, so in the exact same environment, we're going to check both these sensors against each other.

3.5 on the old. Are you going to disappoint me? New sensor and be around 3.5 Yes you are. Yep, Great! Yeah, there's nothing wrong, nothing wrong with the sensor. I Asked my dealer friends for the exact specifications on the Ohm readings and it says not available from Mercedes Um, so that's nice.

but yeah, whatever we found online was I Guess not right and this sensor is fine, but I needed to replace it anyway because I broke the tab so that's not the issue. So a little pull here so it got up to 132 on Sensor 2 and 89ish. Uh, they're on sensor one. See if this recovers, the Mercedes would never recover I'm never gonna financially recover from this.

I'm assuming the higher temperature reading is the intake air that's actually going into the engine and then the other one is the intake air going into the blower. So a little bit of a different setup here, obviously. but either way we'll see if it recovers. Okay, so I'm off the highway now and uh, we're at 105 and 109 so it just recovers almost immediately.

So it got up to like 144 and uh, now this is a good resting heartbeat about. You know it's hot out Ambien is 82 but it's really humid. so yeah, that's how I properly functioning water to air intercooler system should work and we do not have that, but we hopefully can figure it out. I Don't know I've been at this for a long time.

Fingers crossed. The car always disappoints. Me Maybe Maybe this time will be different. Now it's not different.

it's already not different I Don't know I'm tired. Okay, back to the drawing board here. I'm just gonna check this system for leaks. although I don't suspect that's the issue.

We're just going to pressure test this like a normal engine coolant system. So we have our pressure tester and we'll Pump It Up Yeah, let's go about 13 14. I think that's good. I'm going around right now making sure that none of our connections are leaking Under Pressure Nothing there I Checked the driver's side.

Nothing there, nothing a passenger side. Okay, all right, just rolling it out and it's holding. Rock Solid So that's good. Never been so disappointed to see like a good test result.

but every test result that's normal kind of makes me upset because that means we're not figuring out the issue. So anyway, let's move on to another test next on this wonderful, wonderful car. We want to see if the catalytic converters are working. So normally I would use a back pressure testing gauge and this screws right into the front O2 sensors.

but that's the front O2 sensor. You have to drop the entire exhaust. There's no way to like get your hand in there. I Mean it's just everything is just crammed as you can imagine.

So I'm going to show you a method of checking your catalytic converters that may not be as accurate, but it's much easier and you know what? I'm going to still show you this back pressure tester on that. My LS Mercedes has just about the easiest fronto 2 access ever. So we're just going to take this sensor out. Hey, looks pretty good.

We're going to unplug this sensor as well because this is a heated O2 and you don't want it to melt anything. They get really hot and then we're going to Simply screw in our test fitting and then we'll install the hose for the gauge. We have the clamp tightened up and we're ready to start. the engine pretty much be at zero PSI of back pressure and being naturally aspirated, this should stay pretty low even when we drive it.

It's kind of a dummy gauge, but if you rev it up a little bit. I Mean really, you shouldn't have any back pressure at idle in the exhaust at all. On turbo cars, you might have some, and we'll go over this a ton more in a future. Buick Grand National Video But on a turbo car, ideally you want a One to One ratio.

so if you're running 20 psi of boost in the intake manifold, you shouldn't have any more than 20 psi of back pressure in the exhaust. The lower the better. But typically on a normal car you'll feel bad. Catalytic converters sometimes you can't even get out of your own way.

You can't go over 20 30 miles an hour. You floor it all the way and it's just it's just it just kind of bogs down. I Don't think we have that with the CL because if the intake Air temps are in check, we can rip it and it feels really good. So I Don't believe the cats are bad, but let's go rip it and Laser them.

We're going to see the temperature and see what we can figure out there. Who knows, maybe they are slightly clogged? We're on the driver's side Catalina converter and the front of the cat should be cooler than the back of the cat. So let's see. we got the pipe leading in is 300 and 308 and if this is working properly and doing its thing, this should be much hotter.

Yeah, okay so that looks good to me. Okay, passenger side: yeah, 290 and after the cat we got 5 12. Okay, the exhaust doesn't smell. usually when cats go bad, it smells just like rotten eggs.

We don't have that going on, but at this point we gotta check everything. Engine fans are going crazy. They are on high so they're sucking right through the heat exchanger. This one right there.

The side of the heat exchanger is 128. this side should be cooler. Yeah, we have a 10 degree difference across the heat exchanger. I've seen better I've seen worse.

So I don't think that's it. One last test before I burn this car to the ground. We have a wide band O2 sensor with our little exhaust tailpipe clamp and on some cars we don't have a pass through the trunk, you just tape it to the side of the car like this. This is just a wide band setup that you can take around with you so it's just spliced into a cigarette lighter adapter so we can take it from car to car.

So right at idle, it's running great. stoichiometric I Drove around to get intake air to 130. Let's see what kind of hit we can get that's wide open. All right, That's all we got.

All right. Well, we're on the stock tune with slightly larger injectors. Uh, so I was running low tens normally I'd want to see like 11.5 but again, it's not. We're just on the stock tune just to be as safe as possible.

So if anything, that's rich which definitely would not increase uh, the exhaust gas temperatures which then could in turn make the intake air temperatures rise. But yeah, I Didn't suspect that to be the issue because it never recovers. So even just sitting here idling, the whole system with the fan on should be cooling off. and it's just.

it's just not doing its thing well. Ladies and gentlemen here. I Stand in front of my CL65 AMG as a defeated man and if you guys have been around for a while and you saw my crazy crazy series on fixing everything on this car from a couple of years ago, you know that this happens sometimes with this car. It just throws a bunch of wrenches at you and you get stuck on problems and they're really hard to diagnose.

That's exactly where I'm at right now. I Really don't know what's wrong with this car at the moment. Uh, next video I Am going to have to drop the exhaust. We're gonna have to get into back pressure testing to see if it's a turbo issue or maybe the cats are clogged.

but I am glad that we swapped out the spark plugs and closed the Gap although I don't think that was the issue right now. I think it would have been an issue once we put the tune in this thing and up to the Boost and the timing and all that kind of good stuff so we needed to do that anyway. We have rebuilt coils in this and those were really old coils. We have a brand new pump.

that one was from 2008. I Do think it was weak because we were able to get way longer pulls. I mean we had a few of them in there that were like two to three gears long which is crazy so I do think that helped. Um, but I'm a little stumped I think the system is bled out.

Maybe in the next video we'll try the actual Mercedes tool. I'll have to go borrow one I don't know but in the next one which may take a while to come out, this car will be fixed and it will be on the dyno and we are going to finally complete this series. That's what this video was supposed to be. My Dyno is actually scheduled out for tomorrow I've been on the calendar for a long time, but I'm going to that now.

So anyway, another disappointment. but uh, hopefully you guys weren't disappointed in the overall video. And if you weren't, give this video a big thumbs up. share the video with your friends, subscribe if you haven't already, comment down below what you think is wrong with the car.

I have the best subscribers, the best commenters ever, and a lot of times you guys figure stuff out down there which helps me greatly. So let me know what you think and most importantly have a way better day than I'm having right now and I'll catch all of you in the next video. Foreign but but in speaking with the guys, but in speaking with my friends at V12 and you can use one of these and it and you could definitely use one of these gappers. But I just like was I realized that I realized this went much quicker I realized that this went yeah I realized this went and it is time for our rebuilt.

Yeah and it's time for our anyone. Focus Well my glips. Well my gloves are ripped so you know seven or eight of this cylinder. Seven or eight of this 12..

look at this 2008, this is a two this is. Oh, look at this. Yeah, now what's great is I Not now I haven't installed my Whipple now I haven't I'm borrowing this from you I'm borrowing this from you. Does that make sense I think so this is the this is by far the most.

This is by far the most. This is by far the most. Uh, maybe I can. maybe um I just want to double check.

uh that it hit that. So even though it looks like our pump is Flowing a ton of fluid I just want to double that. Yeah, that's what a normal system. Yeah, that's how I that's how that's how.

I which could in turn then make the engine which could in turn which then it. Oh.