I Thought I Finally Fixed My CL65 AMG! INFURIATING Problem With My Twin Turbo V12 Engine!

[@LegitStreetCars]

Ok, everyone. What in the world do you think is wrong with the car?

[@7g6_66]

It’s German

[@PLdemorygray]

It's just jealous because you parked the McLaren next to it.

[@racekorthings7165]

You need to remap every computer in the car, it can still remember it’s stint with Hoovie!

[@adamhonda98]

My friends dodge ram be like this 24 plugs per cylinder

[@0-60STYLE]

Well, I think it's broken. That's what's wrong with it Alex. Sheesh.

[@sirretsnom3329]

I am so glad you have done this series on the CL63. It has stopped me from buying a used one regardless of how many things I love about this car.

[@0DeadSoul0]

Favorite line in the video "One last test before I burn this car to the ground." Been there done that.

[@DouEditz]

😂

[@marknelson8724]

That was the fatigue talking.

[@yogisingh2504]

As you have installed better and bigger turbos than original, the new tubros are compressing the air at faster rate and producing more heat. The oem water cooled intercoolers are designed or matching to the original turbos on the car. If you think about it, as you drive the car normal condition the system is working fine. After some hard pulls the intercooler system are not able to remove heat fast enough. Onces that point is reach you have to let the system rest or cooled to make it function again. It just a thought, the current oem intercooler are not robust enough to handle the extra heat.

[@dasht2741]

that is a very good point and one that is easily over looked

[@robertevans9354]

I think your on to something

[@Truthcanbeconfusing]

Others have upgraded turbos and and sufficiently cooled the air intake temperatures with the stock intercooler system

[@lexus_offroad_adventures]

Response to the intro: Yes, I’ve had a car like that. But I learned SO much about cars/repair because of it. I can only wish I had the skills Alex has. Then no car issue would intimidate me lol thanks for taking us along for the ride and showing us that Master-tech thought process!

[@electronicsanta8149]

Old school home garage video!!!! Sweeet!!!

[@kenjkbs]

Lol the price of parts are on another level.

[@tschuuuls486]

Hey Alex, check if the cooling fan has the right wattage. On the ML W164 V6 for example there are different wattage fans available, depending on if the car comes with a trailer hitch from the factory. If you retrofit the trailer hitch, you have to replace the fan. The ECU doesn't monitor the fan current, though. So it doesn't know if it has the correct fan at all. Maybe someone replaced the CLs fan and ordered a much cheaper one from a lower spec car?

[@Rev.Match.Reviews]

This honestly seems like it might be the solution. I bet most CL fans fit, and none have to keep up with cooling a V12TT 😅 I bet Alex say this comment, and didn't even respond as he immediately went to check this 😂

[@MrFredrikLokka]

Sounds like a great thing to check at least! 😊

[@bewernia]

Was the fan even coming on? I don't recall if that was checked. Maybe the cooler fins are clogged with bugs?

[@chrisej5987]

​@bewernia was thinking if I were in his shoes I'd be pulling heat exchangers of and possibly replacing them if they were even slightly suspect.

[@nunopereira3553]

I had one problem with the cooling fan on my w211 cdi. Fan wasn't kicking in and had to replace it. Bought a used one that was scrap and had to buy new on ebay. And with my luck the fan was a 850W one which cost 500£ 😅

[@KamranNamdarpour]

I have a PRISTINE 2005 S65 AMG L with 40K miles, that I LOVE!!! So far the only problem has been the volt converter, which cost me $1K in total, as I changed it myself. Took 10 min.

[@allansanor3515]

If the water to air intercooler is pressurized, check the cap. The spring can fatigue and a standard pressure test doesn't check the cap function. Love the content. Keep it up.

[@NDPhotonl]

That makes no sense to me. If the spring is soft, the system does not hold max pressure and it will spew out coolant. Afaik he has no leaks in the secondary system

[@allansanor3515]

@@NDPhotonl if the coolant swell isn't enough to overflow, it would go unnoticed. The issue would be the coolant boiling point not being raised by the increased pressure. If the coolant boils it can't carry enough heat energy away from the charged air. Not sure if the IAT is high enough to boil the coolant though.

[@jc13781]

I think you could be right, if there’s a small leak on the coolant cap or any other area that could introduce air into the system it could cause the pump to struggle. Would be easy to diagnose as well, just do back to back bleeds.

[@zollotech]

Great to see the CL65 back on the channel and looking forward to the final result.

[@CalculatedRiskAK]

I'd recommend checking the resistance of the wires leading to the intake air temperature sensor. If the resistance of the circuit is too high, it could make a good sensor have an off reading. A wire getting way too hot will raise its resistance, so check the harness and see if it's touching somewhere it shouldn't. They likely aren't the issue, but who knows.

[@tei1337]

Aren't the IAT sensors usually NTC, though? I.e. higher temp, less resistance, and If the wires have too high resistance, the ECU would read too low temperature.

[@tomh.6134]

Hey Alex, I think replacing the pump was probably the right thing to do. I have an 03CL 55 super low miles, the pump was bad 2 to 3 runs, and the car would just die. Lost all power. I messaged you about a year ago on it because at full boost when you immediately let off the throttle, there was some bucking and surging. One of my buddies is an AMG mechanic in Grapevine, Texas, and he replaced the pump and the relay. That returned drivability 100%. I would suggest replacing the relay that drives the pump. It may also drive the fuel. Next thing I would do is I would just disconnect the cats and make a hard run and see if that helps. Only other thing I could suggest is, are you getting cold air from the traditional intake vents that route in front of the radiator. I suppose the inner coolers could be somewhat clogged, but don’t know. You could also try adding an auxiliary one.

[@jasonfindlay8646]

Hey Alex I had a similar problem back in 2005 when I was a young Viper Tech who got the great idea to twin turbo my SRT10 Ram. Try measuring the AF ration from each side of the block not at the rear exhaust exit. My issue ended up being one of the turbos was not performing as well as the other the right side back was producing more boost when running wide open even though they where identical units. This was resulting in the right side back running leaner and heating the manifold on that side of the block, much like you it wasn't something I was able to tell via ECU data and I spent a long time thinking it was my intercooler set up. Final fix was sending my turbos back to be rebalanced to give near identical boost output at all levels of the RPM range. Hope this helps and good luck with the Benz.

[@vinny6_9]

he measured intakes and they were identical, tho he didn't get into boost at idle, obv. even if the turbo was producing more boost, his tune should've made up for it by adding more fuel (he has enough injector).

[@jc13781]

I don’t think that would be it because the car runs fine until it heats up, if there were an issue w one of the turbos you would likely not have the same issue w the intake temps. I personally think the car is cursed.

[@joshuad1716]

twin turbo srt 10 huh?? did you ever make traction lol

[@jasonfindlay8646]

@joshuad1716 Sadly not really I was young it was stupid idea even with 305 wide drag radials and a water weight bladder in the bed I couldn't hook up to save my life. Nothing helped in that regard except taking power out.

[@jasonfindlay8646]

It was a personal experience and on my SRT Ram the tune was not compensating with more fuel. I mentioned it because when he measured the inlet to the cat temps one was higher than the other and an old timer back in 05 said that even 10 degrees difference should of been my give. His words where" if your putting the same stuff in on both sides of the block then the same should come out if all things equal. Then told me but you go by what that fancy laptop be telling you" in the end old Ray was right.

[@markhutchinson3367]

Alex, I would advise to ohm test the original intake air temperature sensor that you removed when you first got the car. The part that makes me suggest that is that MBZ couldn't tell you the ohm test spec on the new sensors. It could be possible that MBZ is now selling a superseded part number that is actually the incorrect spec for your engine. Wouldn't be the first time I have seen this. If your original sensor reads differently than the new ones, that could be it. You also did the thermometer test on the intercooler outlet which showed lower temps than the sensor did. Also make sure the sensor connector and wires in the harness aren't burnt up or broken or shorting. You could also install an independent aftermarket IAT sensor to compare to the stock readings.

[@sibbese3740]

Yes, that would explain alot of the issues. Hook up a external temp sensor somehow.

[@TonytheCarEnthusiast]

reminds me of trying to diagnose a car for p0299 low boost code. The client never told me he replaced the exhaust pressure sensor and i was chasing my tail, thank god i had a different car and compared the values and they’re were totally different, mercedes somehow sells two different sensors for that engine and the client had bought a different one. What a waste of time that was!

[@deankammler9773]

This is my favorite of all your cars. I envy your expertise and optimism in fixing it. Thank you for persisting and telling us about all the problems. On other channels the “problem” cars just disappear, never to be talked about again (:cough: Tavarish lol). Great video!!

[@vadneysean72]

It's weird how his disaster is our favorite project

[@samfuller6273]

I makes it interesting, though

[@lightning95sc]

I'm afraid this car has the Hoovie curse on it. It's never fixed.

[@martinlohstroh]

Like his Bentley.

[@waynekingston7772]

Hey Alex, I suggest comparing your IAT sensor with a known good one from another vehicle- you installed one new during the build and had online info that said it was bad when you tested it, you then replaced it again with the same new item- it is likely the two new sensors you’ve tried aren’t right- contact one of the 65 guys that have commented on here and ask to check their sensor values and compare to yours. Also at 36:37 I noted when you had the Y duct disconnected and had 154degF IAT on your reader, then measured 105 at the exchanger outlet, is the 154 a plausible value given it was sucking ambient air, ie was the air entering the intake really that temperature- guess it’s possible given the engine was hot and cooling fan on blowing hot air, but worth confirming IMO? Seems like the IAT sensor is very close to the intake entry so can’t imagine it’s engine heat soak heating the intake air. Anyway, super easy to triple check the IAT sensor values are correct with a know good one to rule that out. Great video mate, these challenging cars are the most interesting videos to watch, you’ll solve it and it’ll be great seeing it getting a flogging on the dyno!

[@sok_pomaranczowy]

Congrats on 1 mil subs!!! Hope you solve this misterious problem

[@REfanforlife]

alex is so genuine in his approach that i honestly forget it’s a show with edits and stuff i’m always so surprised when the outtakes pop up 😂

[@RANDASH]

Hey Alex, its possible that your pump is turning off, on the E55, the pump is controlled by the rear SAM that talks over CAN to the engine ECU (Who knows who designed this). Any weird electrical issues and its possible the pump won't turn on. You can maybe do a common mod that I've done on my E55, and simply hook the pump power line up to ignition voltage, that way whenever the engine is on, the pump will be on, no matter what. I've had this working on my E55 for over a year now, and the OEM pump is fine.

[@samfuller6273]

I like this idea, but he was doing live monitoring, so I kind of think he'd know if it was turning off.

[@dieselgaint]

That's a really good thought. And if he was monitoring the status it could still not be on. The sam reports one thing but say the relay doesn't respond? I've seen that a few times working cars. Module says it's doing something but it's not actually.

[@kristofkiss1940]

I had a similar problem with my E400 CDI, the IAT would rise up to 85C/185F on the highway, and it would stay there. For me it was a partially blocked intercooler radiator. You should check the radiator, to see if that's working ok.

[@jironmeister]

Same in ML270 CDI, Intercooler sensor.

[@surferdude4487]

Yep. that would be my guess too. But I would test before loading up the parts cannon.

[@sebg1224]

Honestly, I want to thank you for not only putting yourself through this, but showing it to us. This is kind of how my first attempt at restoring a car went. One thing after another, followed up by mistakes and basically every bit of bad luck you can imagine. I spent a lot of time feeing stupid and inadequate. Watching people like you go through similar situations makes it feel a lot better.

[@emtpayislow]

Agree with this sentiment 100%. Sometimes you just get your ass kicked.

[@johnnieacosta7238]

I miss my old 60s and 70s cars No freaking computers

[@elevn11]

Love to see your troubleshooting process and even the unsuccessful attempts. Great episode, thanks!

[@amfautomotive5710]

@LegitStreetCars I once had a M275 do this same thing. In my case, the turbo wastegastes where unsyncronised and where causing increased backpressure on one side of the engine. I only had misfire codes 4000RPM+ at full throttle. Sometimes all one bank, but often only 3-4 from one side. I applied 5psi to the wastegate lines and syncronsied the wastegate actuators so they moved the same amount by adjusting the rod length on both turbos, then reset the adaptions in ME. Been rock solid for 3+ years now.

[@KH-fi1fn]

I think you need to validate the actual intake temp with a separate unit. I would get a fluke meter with a thermocouple and side into the intercooler outlet. Measure the actual temp. If the is resistance in the harness it doesn't matter if the sensor is good or not.

[@ampsandoctane]

thats a good idea!

[@liuj88]

36:50

[@edoardopassera]

Hey Alex, can I suggest to give a shot at my theory. Try to feed the pump water with ice from a bucket and make it somehow return in the same bucket. If it still rises the intake temp you have another issue which is not related to the intercoolers.

[@sylvain.robichaud]

My nightmare car, Alex, is an Audi A8…amazing car, luxurious , somewhat understated, and oh surprise, so complicated. Every time I finish fixing something and think the car is finally good to go well, something else needs attention! I truly appreciate you man!!!

[@MrReese]

The complexity and amount of work you have to do on this car is crazy 😯.

[@Globbs]

24 spark plugs. hahahahaah

[@Mr.Mitch1111]

Prime example of how the toughest problems are also the most interesting, at least for your viewers, and because I feel that we learn the most, just as do you.

[@jesseframe5134]

I deleted my ABC setup on my 2006 S65 & installed coilovers, thinking of adding another OEM oil cooler/ fan assembly in the vacant space leftover from removing the ABC manifold. this should increase engine oil cooling substantially & maybe yield an overall 10% reduction in susceptibility for heat soaking. going to ditch the tandem pump ABC exchanger & see if that space is better used for a larger intercooler heat exchanger for heat mitigation.

[@ampiko68]

Great to now. How is the ride impacted? Did you put in a sway bar as well. Could you provide the coilover vendor and how many hours it took? Thanks

[@jesseframe5134]

@ yeah, I converted over tho the AirMatic 5x rib stand alone power steering pump, AirMatic sway-bar/ anti-roll bars, AirMatic FLCAs (Front Lower Control Arms) I went with Ceika, as I was their first customer to install coilovers on a W220 with ABC (Active Body Control) I reused my old power steering reservoir, with some creative plumbing & modified the original power steering line from the pump to rack (required cutting the fittings & adding a section of hose) I did a whole write up of the swap. I also had to make custom spacers for the AirMatic power steering pump, to make sure the 5x rib pulley aligned with the rest of the 6x rib pulleys on the rest of the engine. I spaced it from the rear of all the pulleys. going on 4 years now, with no problems.

[@ampiko68]

@@jesseframe5134 Glad to hear that there were no issues. Any major over/under steer and is the ride quality ok? Did you post the write-up somewhere?

[@jesseframe5134]

@ it’s mostly fighting body roll. The car naturally wants to oversteer, when pushing it & the M275 generates enough power across the RPM range that you can really just steer with the throttle. Due to it being so long, it reacts very slowly in regard to oversteer. The problem is transitions from left to right, the body roll rate so much momentum that the car seems to understeer, but you can just throttle it back into position. A proper LSD conversion is a game changer for these cars, but even the RENNtech 1.5-way LSD I have needed to be tuned to have better lockup. Honestly I wish someone would make a proper 2-way LSD for the W220 (I wonder how compatible this LSD would be across the Mercedes lineup 🤔) The things I do to my car, it was never designed or intended for. After numerous failures to complete a single track day, I decided to simplify & sacrifice some of the handling characteristics/ identity of the “S-Class” But it now survives a full track day & it’s not a slouch. I always end up somewhere in the middle of the leaderboard. Not bad for a nearly 5000 pound luxury sedan. It’s funny because I also have used an older W220 S600 (M137) to tow my FD3S to track events. I need to source an OEM tow package for the W220 & see if I can get it to fit on an AMG trim level car (lots of exhaust routing might not make it a possibility to mount the tow package) because I’d love to pull in to a track event witg the S65 & the FD in tow.

[@beresfordthompson1370]

Hey Alex, love your channel. I’d have to say you seem like the most patient person I’ve ever seen. You always seem upbeat and don’t curse, swear, throw things around when things don’t go your way. I’ve seen a lot of channels where the people swear, hammer on stuff and throw a tantrum when shit don’t happen, but you are so in control. Hats off to you for that, it makes for better viewing not seeing the anger and aggression of other channels. Good luck with it, I know you’ll figure it out in the end.

[@ozymandias7940]

It's called 'editing'. I'm sure Alex has his moments off camera.

[@beresfordthompson1370]

@@ozymandias7940 possibly, but I’ve seen a lot of channels, and they are good channels but the thing that brings them down is the do show it on camera and some of them are quite excessive and the language that comes out is sometimes offensive. And yes I swear from time to time so I’m not easily offended but when it’s every second word and some over the top hand gestures are offensive and unprofessional.

[@TheCoolDave]

@@ozymandias7940 Same thing I was thinking. Everyone has their breaking point and this car, i could see him losing it....

[@chriswiesinger3187]

Hey Alex, just a theory. Larger injectors; under boost; the ecu is reading it as fat then trying to lean it out, and by the time the ecu catches up it looks normal. Like a micro lean spike. Not sure if fueling or AIT “logic” / Safety’s can be adjusted in the tune. Hope this helps; fingers crossed

[@bernardwarr4187]

Interesting idea

[@petere3015]

In 2008 I purchased a 2001 CL 600 Palm Springs car with 91K miles. I shipped it to Kuwait where I had a job lined up. Within a couple of months the car developed a horrendous engine oil leak, like a quart every 30 miles! I would never have purchased this car for use in America as I was very aware of the unreliability and expensive repairs this car required here in the US. But in Kuwait the country is full of Mercedes repair shops and labor is cheap. Fair enough, the repair shop I took it to brought over the top Mercedes agency mechanic who moonlighted and fixed the problem. I never understood what was the reason for the leak, language barrier prevented proper communication, but when I visited the shop one night I couldn't believe my eyes, both cylinder heads were off the engine. Which makes me wonder perhaps that it was the same O-Ring you mention in your video. I went on to use the car for six years without any more problems except for the occasional electrical gremlin. So, what was the O-Ring sealing?

[@user-Venom-WTF]

Yes 😊

[@eugenekharon]

Thanks for the video Alex. I have a silver 2005 CL65 in Morton Grove if you need it for comparison... I know there are not that many around locally for you to look at if needed. I had a similar issue of the engine cutting out but my "certified Benz mechanic" fixed it with new coils and spark plugs. You seem to have a different issue. Also, I can show you a few quick aftermarket mods I did on mine (for an "easy" post-fix video idea) :) Hopefully, you solve it on the next one and take it to Chicago Auto Pros for its final dress-up. PS. The cup holder on your car is broken but I am sure you already knew that. It should not swing like that.

[@daveh2612]

What shop do you use?

[@inftech476]

Seen a couple people say it but you should separate the heat exchanger from the radiator and the condenser to check and make sure there’s no built up dirt or dust. Same thing as when a car overheats with the ac on! Good luck!

[@evmotorsports]

Had a s600 , heat soak in inter coolers is standard on this gen especially tuned. Put a 5 gallon tank in spare tire well run 3/4” hoses to pump and swap pump to q7 replacement pump( available from Germany for 220$ ,huge volume increases ,and with additional volume you will never go above 120 , even at the track.

[@charlie1832]

This is my favorite car on the channel, I want to see you get this thing perfect then take Hoovie for a ride to show him what he could have had

[@darrenwhite5544]

And then you'll get the banging on the hood followed by the Words "How much?"

[@bonose12]

Hoovie sleeps at night, Alex has CL nightmares.

[@JACB006]

@@bonose12Hoovie just flips cars and get’s rid of the good ones, EG CL65 and DS21, Alex and the Wizard have the fun videos and share knowledge working out the issues.

[@jc13781]

I don’t think any amount of free rides will make hoovie jealous in any way after seeing all the struggles. He will just take his COUNTACH for a spin and be happy in life.

[@JACB006]

@@jc13781 a Some like simple shallow pleasures, some like something more involved. To each their own.

[@stevek2858]

I’m not sure the intake temp has anything to do with it, It may just be a proxy for boost. With it running great until you get under high load I’d really be looking at fuel pressure and ignition. Whenever I have a weird problem I try to eliminate any aftermarket add ons to verify operation. If you can I’d try to swap out the ignition components with OEM stuff for diag. Also if you suspect a clogged catalytic converter you can loosen the pre cat A/F sensor, then go beat on it, if its clogged it will make a loud hissing sound, and sound different from B1 to B2. BTW I’m a dealership Gold technician

[@chrisbrown1462]

Good point...we are only thinking heat because that one sensor. It could just be a misdirect. Maybe look at another CL65 and see what it's sensor is showing..

[@dieselgaint]

That's a good thought. With my e55 if iat got too high it would just derate not start misfiring. What's a derate look like for a cl65? I would guess not multiple miss fires like Alex is experiencing. Unless it just goes straight to limp mode like that.

[@stevek2858]

@@dieselgaintI can’t speak with authority on Mercedes Benz, but most German cars will deactivate a cylinder by shutting down the injector to protect the catalyst, if the misfire counter goes over a preset threshold. This is reset when the ignition is cycled or not fault is cleared

[@toeknee2u]

Is the intake coolant radiator the original? - If yes could there be a blockage restricting full flow? - If no and it's a replacement is it possible that coolant flow is incorrect. - i believe some radiators have 'directed flow' so that the full surface area IS utilised: If it's meant to be d/f but isn't, coolant would take the path of least resistance and may not be cooled properly. - you might diagnose a high temperature 'path' over the radiator surface area...

[@ROBIN_SAGE]

I give you a TON of credit, I’d rather gouge my eyes out than work on this thing. I very much enjoyed watching your troubleshooting process :)

[@DennyMartinsson]

To start with, you are making awesome videos, spreading knowledge at the same time making good videos with some humor. Also congrats on the million subs 🎉 I have worked on many many mercedes lcv and trucks. As far as I can see you have checked the sensor. I would check the cables at the connector for the sensor but also for corrosion on the pins. If thats good I would backprobe the signal pin on the sensor and checked that its the same that the ecu sees. Have had some wiring issues on the om651 engines. Not the same engine at all but could have similar issue. Mercedes still uses very thin wires anyways. If thats good I would put extra sensors in the intake pipe from the intercoolers, maybe even on the turbo side. Like k type thermocouple sensors. Logg that temp to see if the sensor actually gives the real temp and at the same time see the performance of the intercooler system. Just my take on this without being there.

[@_zigzak]

Alex I gotta say as someone who has dreamed of owning a “65 amg” car, this series completely changed my mind in ever wanting to own one 😂

[@CheeseballsWizard]

Literally me fucking too lol

[@robertevans9354]

So do you still want one or not?

[@MM_in_Havasu]

I installed a turbocharger on one of my motorcycles, had to regap plugs clear down to .020" from .035" to eliminate a top end misfire under boost. That engine shot ducks(backfires)that would have made a hunter jealous! Smaller gap cured the problem and the bike then ran an indicated 171 mph on GPS with no misfires. Great video! Thanks Alex!

[@ecapproved4225]

Wowza, what bike?

[@brnktv]

The cupholder is designer to anti-tilt. You go hard right, it maintains upright position by forcing itself left. It's not a bad design actually.

[@haydowayne]

Im driving a 2007 s600 with the v12 twin turbo no missfire no codes at all no leaks perfect condition all the electronics work

[@user-Venom-WTF]

Alex need to watch the temperature of the fluid in the intercoolers that is circulating. If it is high, then why think and look for a problem elsewhere ??? Of course the intake air will be hot if the fluid is hot)))!!! Put a temperature sensor on the fluid in front of the intercooler. Maybe one more after the intercooler. Look under load on the road what this sensor will show

[@haydowayne]

@@user-Venom-WTF ive had a problem with that temperature sensor before on a different s600 ive owned did he ever replace his temp sensor in the video it looked like it was hanging out of place but plugged in

[@FransvandenBergeMuziekschuur]

It is a lot of fun when you are in your zone of problem solving. Excellent video.

[@wurly1]

Good to see this car back on the channel (and the OG LSC HQ!). Really admire you sticking with this one, looking forward to you getting to the bottom of it and finally fully fixed!

[@hvacrtexas5281]

Hi Alex, I ran across this issue a long time ago, from everything you've done, I would say your heat exchangers are dirty and not transferring heat properly. Take them out and wash them or send them out to be boiled at a radiator shop. I hope this helps you out.

[@ryandoyle4344]

Although, boost was showing IAT rising, the IAT's were increasing at idle & with no boost to >150° before the sensor was replaced. Something is causing temperature rise in the intake; Check the coolant lines to the intake plenum & associated flow. GL

[@ummduhgmail]

It's the fact that it's in the intake manifold. At idle the air flow is so minimal that it allows the air to heat soak due to the mass and heat from the entire engine. I typically put the iat in the plumbing instead of the manifold.

[@ummduhgmail]

Once off idle it should drop like a rock though

[@zedwolf5556]

I would continue with verifying temperatures. Add more temperature probes to the system. One in the Y pipe where the turbos flow into the intake, one in the water side of each intercooler, one on each side of the front mount rad for the intercooler. Something you can monitor while doing a pull to verify that your built in sensor is reasonably accurate, and that you have reasonable water temps.

[@dieselgaint]

Exactly my thought. More data is needed than what the scan tool is providing. Should be able to get surface mounted, stick on, thermocouples.

[@corywillis1772]

The bloopers said it all. No lack of effort in this video. I feel for you man!

[@bentickner1]

vacuum lines are a problem after you upgrade the boost. smart to upgrade the coil packs they are wear items and really mandatory when adding a tune. I would guess your cats could be an issue and worth checking because its easy. Borrowing a STAR diagnostic tool is a good idea but you also need a good 65 knowledgeable mechanic to show you what to look for. they did not make a lot of these engines overall when you think about it. 2005 was the first year and my favorite as they are less complicated than later years and easier to keep power to the wheels as there are less controls to electronically limit it. I put a lsd in my cl65 and when I sold it I went to a 2005 sl65 (the sl 65 comes with an lsd stock) I ran into so many 65 series related engine issues and my saviors where the tuner gods. I luckily have great relationships with 3 of the companies that tune the 65 series engines and everytime I talk to them I learn another crazy fact about this powerplant. I wish you luck on this quest and am sorry I cant be more help at this time.

[@AndrewNoronha-cb2gy]

You could try connecting a resistor instead of the air temp sensor The value of the resistor would be proportionate to what temp you want it to show (100 F) then you can test to see if the problem still persist

[@99domini99]

This often won’t work on a Mercedes. These computers have so much cross-referencing and self checking that they have a very good idea what the value of a sensor should be, and at even the slightest discrepancy they disregard the sensor as defective. Makes ‘m a pain to tune without flashing the ECU.

[@NirreFirre]

@@99domini99I guess using a pot (in the right range) can get you within the MCU spec? An analog one + Alex's soft touch = magic?

[@99domini99]

@@NirreFirre Possibly, I haven’t had any luck defeating Mercedes computers.

[@BMWBuilds]

These videos are super motivational. Thanks for keeping on the CL65. Definitively a childhood dream car of mine, and I love this channel as a result of even just your CL65 content. You keep it light and fun. Love it!

[@lokijones8324]

You could have a few problems that you are not looking at. The aluminum of the radiators, or the intercoolers could be clogged. Not the coolant pasages, but the aluminum itself. If that has happened, the cooling capacity of any of it is shot. I had a car that had that happen to the radiator. Chased it around, and around, and what finally fixed it was replacing the radiator. Check that.

[@ccarlock8537]

Tons of air bubbles in there

[@quantumtime6883]

I believe the issue involves the welded water jacket that was discovered during rebuilding the engine. There could be a minor internal coolant leak or some debris impeding coolant circulation allowing the intake manifold to heat up. I have a sneaky suspicion that the issue is internal as all the external components have been ruled out. Good Luck

[@azargelin]

Thar hile was in the head. If there is a probkem it would overheat the engine

[@imfloridano5448]

Two separate cooling systems

[@Constabruity]

@@azargelinshould I call emergency services on your behalf?

[@j.d.8593]

Noup, not even close, the problem is the heat exchanger for the intercoolers, not the engine, they are 2 separated systems.

[@rwduece122]

The welded water jacket is for the engine coolant, and the systems are split, no? So im pretty sure that specifically cant be it because they are seperate systems. Im also pretty sure the entire intercooler water cooling system is external there is no internal part of this system.

[@RSPYT]

It’s called a charge cooler, not intercooler. Intercoolers are air to air and charge coolers are water to air with its own water pump. They’re not as efficient as intercoolers which is why most people replace charge coolers with a good quality intercooler. I did the same with my MK1 Focus RS and it reduced temps massively and helped it make More reliable power too.

[@sinoverlord409]

Had a car that wouldn't start in the morning. It would sound like it had no compression. This is back when I worked as a technician at Lincoln Mercury Ford. Replaced the heads,and the car ran beautifully. But low and behold in the morning, it wouldn't start with the exact same problem. Car sat for a month we just couldn't figure it out. Turns out the vehicle owner was a teacher and someone had put sugar in the gas tank as we would later find out 😂

[@zollotech]

The Rivian is ok. I had one for 6 months or so, but not a truck guy. Got rid of it for something else. Kind of did what you did with switching from electric back to gas.

[@Taydrum]

I know a couple of people that own them, sure they're decent, but the fuselage is monocoque. A buddy that was rear ended (minorly) had to fork over 45K to fix it, because you can't replace one panel. You have to replace the whole body. Needless to say insurance was not going to cover that and they dropped him. He had some issues getting anybody to insure it after that, and he so he got rid of it

[@v.j.1017]

Ya it’s nice

[@hitardo]

Alex, we stand with you! I really hope you can enjoy this car more, because you deserve it, and because this car is lovely when running right. Cheers!

[@erich6879]

I would HATE to figure how many man hours you have in "fixing" that. Maybe you should have your wife drop it off at the dealer and have them fix it...just for fun to see if they can do it, AND find out what they would charge LOLOLOLO LOVE the channel, I've been a supporter since the beginning!

[@tjnucnuc]

Those laser iridium plugs are great. They are OEM for the Abarth which is big boost (26 psi stock) and very high temps. But to avoid blowout you need to torque them to at BARE MIN to 17ft-lbs. The crush washer won’t even crush until then and most tuners recommend torqued to 20 but that always feels a bit excessive to me. I hope you see this and hope you realize that the normal “snug and then half a turn” isn’t enough to avoid plug blowout especially boosted. It’s a SUPER common issue.

[@lakeminnetonkaoutdoors7532]

ALEX DO YOU THIS IS COMMENT???????????? THIS IS YOUR ANSWER

[@ovlov91]

This is not what spark blowout is. Like not even close 😂

[@tjnucnuc]

@@ovlov91 yes these plugs specifically in boosted applications are known to blow out easily at least in the cars they are commonly used in. It’s happened to me before. just doing the normal finger tight half a turn trick won’t crush the crush washer on these. Over time they work themselves loose and allow the exhaust to blow past the plug and many times this also causes the plug tip to destroy itself and fall into the top end.

[@tjnucnuc]

@@lakeminnetonkaoutdoors7532 well this doesn’t have anything to do with his coolant issue it was just of note.

[@kylebaker4354]

They spark blow out he is talking about is because of the boost pressure. More boost makes the spark hard to cross the gap so closer gap is neccessary. The boost pressure is nothing compared to the pressures created by the combustion pressures inside the cylinder.

[@garyrains5996]

It is such a great lesson in learning watching you Alex. I am sure you will solve the issue with your CL. However, I will point out to your subscribers that these cars can be and are great to own. My 2003 CL600 has never had a suspension problem, it has the original turbos and it has always been fast enough to pull the hair plugs out of your head. I did have a problem with the trunk not opening correctly so I took it to Mercedes and they fixed it. My biggest problem is trying to stay anywhere near the legal speed limit. It adds drama to your regular run to the grocery store wondering if you are going home or to jail! Great video.

[@juancarloslozano3374]

Hi Alex! I think it's the ECU. Last gen Saab 9-3 came with the ECU above the intake manifold-, lots of heat-, so the constant heat fries the computer and it leads to a misfiring and floods the Chambers with gas cause it leaves the injectors open. Solutions it's an ECU replacement and also a relocation out of the engine's heat. This happens to my 06 Saab 9-3 2.0 SS

[@N.D.J.S.]

couldt be --- the m273 has the same problem.

[@joeblacklv]

My money is also on the ECU or damaged wiring somewhere in between.

[@MattWeaver909]

Love to see a fellow saab friend here

[@juancarloslozano3374]

@@MattWeaver909 I learn tricks from Alex, like today the tool to adjust gap on the spark plugs! Cheers!

[@dailyg2719]

Ok Alex I still think it has somthing to do with the injection. I know there not related however it's certainly a rich misfire due to larger injection without tune. That will give you a hotter exhaust due to fuel dumping and misfires. My gess is go get a tune done for fuel correction. One problem is masking another. Yes still could have a tiny air bubble 🫧

[@jessepannabecker3456]

This is why we’re here! It doesn’t have to be all roses and daisies. You’re a fantastic diagnoser. This is coming from an Acura tech. This part of our industry is the hardest part.

[@demoralizer1]

Hey Alex, long time subscriber here! I had a similar issue with my 2003 S600. You can't take out the Schrader valves to bleed the intercooler, as that puts air into the system. Any air will mess it up. Happy to chat you through my setup to bleed the system without using the factory tool!

[@Truthcanbeconfusing]

Please explain your method of removing the air from the intercooler system, I have a 2013 s65 AMG and I need to remove the intercoolers to replace the engine mounts.

[@jc13781]

I think you need to test the ohms on a known hood temp sensor from that era. I suspect maybe the part itself is incorrect and there just aren’t enough of these on the road.

[@ejsgarage]

Respect! You have a lot more patience than me when it comes to restoring a car brother! Your skills are amazing! Those coil packs and 24 spark plugs alone steer me so far away from the V12 Mercedes hahaha.

[@SpeedandPowerLuxuryCarGarage]

I have an idea. You have two temperature sensors. Leave one in the engine. The second one attach to a extension and keep the sensor I don’t know in the cabin may be nice and cool 😂 or somewhere the temp is not that high. Go for a test drive. If it works then we can look at the next step. Have to be really sure that yes the car does that at that temp sensor reading.

[@janbevelsborg]

Like these kind of video’s Alex. The more difficult the issue the more satisfaction when you get things solved in the end. My current struggle is an M102 engine from 1985 down on power. Hope to get this fixed in the following weeks

[@benzlover55]

Does it have a catalytic converter? It might be plugged. I have a 300SDL that was severely down on power, turns out some dummy put an after-market cat on it and it was destroyed, emptied it out and it fixed it.

[@Duckswag87]

Fascinating. I had a truck 10 years ago that I spent thousands on trying to fix. Everything I did improved the car but it had this mysterious electrical problem where it would go in limp mode, shut off and take 5+ minutes to start again but then would run perfectly. I literally did everything from coil packs, plugs and wires, 02 sensors, solenoids, throttle body replacement, distributor module and much more. Some days it would run perfect and other days it would just shut off on the interstate and I’d have to bump it in neutral and try starting it while coasting off to the shoulder. It never left me stranded but I finally sold it for a deep discount to a dad that thought he could fix it for his 16 year old son. I gave him a really good deal and the file with over $4k in receipts for all of the repairs I’d done. That cost is all DYI, I have no idea what happened to it, I never heard about it again but these stories fascinate me

[@maxdrelinger]

Had the exact same issue with my S65, it was the intercooler pump. The impeller split on mine.

[@martinllanos4998]

I think you need to datalog and do a strong pull before and during the fuel cut/ limp mode. You gotta see what the timing is doing and also check fuel trims.

[@mattj20]

I’d imagine it’s pulling timing from the high IAT and because it’s already rich from the wrong tune from the bigger injectors it’s causing it to misfire

[@markwarren625]

Thank you so much for the time & effort you spend in these videos. I have an SL-500 and two Cayennes, so I feel every pain and aggravation that you go through when repair events don’t happen according to plan. However you are pure comedic genius, I can’t help but laugh at your pain & suffering. Sorry, I routinely go through many painful episodes on German car repair & maintenance, but I don’t handle the stress well at all. You on the other hand maintain incredible composer in front of the camera. For us motor geeks you are extremely entertaining, more so than most anything on television. Keep up the good work, keep up the great attitude. Us German car owners will go broke together, but some will maintain their sanity better than others.

[@darinworthington]

Would be worth getting a flow test done on the Water to Air system as it can have a clog/blockage.

[@austinaubinoe2195]

This is just insane to follow. Never in a million years would I buy a car like that (maybe a V12 E38), but it’s so fun to live vicariously through this process. The quad air intake filters is just so freaking cool!

[@michu6777]

I recommend the E38 V12s! They're pretty reliable and super easy to work on and diagnose

[@koenradmacbride7158]

I'm sorry you're having all these problems, but selfishly I'm glad for it because it's helped me diagnose some ignition stuff on my own S600. Love your videos.

[@matthewmcmaster2731]

Could you look into installing a higher flow coolant pump (aftermarket)? You would have to wire on a factory plug end on the pump or just run a manual switch into the cabin. That way the pump could run all the time (they might already...I don't know). It would be worth a shot. You could test it out before committing to a full install. Just an idea. You might have thought of that already.

[@Scalaflow]

I was looking forward to your further episodes on the CL65, thought you might have given up on it !

[@alexholt4148]

I've had my CL600 for 9 years I feel your pain, took 2 months to finally fix secondary air code issue. But keep the faith you got this!

[@gazgrob]

Hi Alex ,great video as usual .I’m no expert but reckon it could be reduced coolant flow through the heat exchanger as the you didn’t have much variation between intake and outlet temp. my guess is that as the fluid temp rises the narrower the temp difference between inlet /outlet becomes due to a flow restriction ,therefore overall temp does not reduce fast enough between the high and low software temp presets during cooling cycle.

[@RylandBingham]

This was thought as well. It’s flowing but not through all the fins?

[@MrCarGuy]

Sensors are often overlooked. I always like to eliminate the sensor being at fault before diving deeper

[@tonyoliver5537]

It's your blow-off valve are waste gate it needs to be updated are increased with maybe an aftermarket if availiable.

[@rotrmotr]

Hey Alex. Check the heat exchanger and the others in front and back of it to see if the fins are clogged. You should be able to see light through them all. Relocate the second IAT sensor away from the center top of the engine. Engine heat is adding to the sensor's temp reading. I hope you find the smoking gun soon. Good luck!

[@romans7177]

In my opinion it could stem from the ported head, prior in the video you mentioned that a hole was found in the water jacket from the porting. So what i think is going on is the walls of the intake valve and the area leading up to it are getting super heated by the engine coolant thus rising intake temps and causing some of these problems possibly. Which this could be the worst scenario which means the engine leaving the car and the heads having to be replaced. I'm no genius but I think it could be my hypothesis.

[@XcoolcoolbeansbeansX]

The temperature in the intake ports is not measured by the car. The IAT sensor is well before the ports.

[@TonytheCarEnthusiast]

stop talking through your ass. wish only mechanics would give advice here. because of people like you, mechanics get double more work because they always fuck they own car up trying to fix it.

[@N2_WIN]

Look at the w216s intercooler setup on 6.5 liter bi turbo motor. I believe Mercedes corrected this heating issue on their later v-12 turbo motors. The intercooler placement (on top) over the intake manifold is awkward. While it is air/Water cooled that motor produces so much heat. Objectively you should be looking to promote Cooler air into the engine compartment. Possibly increase the fans size/speed so as to get that temperature reading down. Maybe a custom air slotted hood? Or a funneling system that brings in cool air into the Y fitting. You’re gonna need to customize something, since you’ve already posted heads and larger turbos it’s just getting hotter (increasing temperature). Just my opinion… but great content so far! I’ve owned a w215 and w216 and there beautiful cars when fully operational!

[@user-Venom-WTF]

Alex need to watch the temperature of the fluid in the intercoolers that is circulating. If it is high, then why think and look for a problem elsewhere ??? Of course the intake air will be hot if the fluid is hot)))!!! Put a temperature sensor on the fluid in front of the intercooler. Maybe one more after the intercooler. Look under load on the road what this sensor will show

[@user-Venom-WTF]

What different w216 amg 65? It’s same…

[@NCCoder]

That the iat got up over 150 with the Y pipe not installed is a red flag to me. The location looks to be right behind the throttle body so should be reading much closer to ambient. Is it possible there's some sort of insulation missing between the intake manifold and the sensor itself, or a part number that's wrong?

[@samfuller6273]

I wonder if he has the IAT that was on it from Hoovie? The original one. Just to see if it's different.

[@slaytalera]

@@samfuller6273 He thinks he replaced it when he reassembled the engine but he replaced it again later in the episode, I was convinced the IAT sensor was the culprit here

[@whylee3686]

Its the (upgraded) turbos and the factory intercooler setup most likely. Your air intake temps are too high and not recovering is most likely due to the turbos making too much heat for the top mounted intercoolers and they are staying heat soaked. Im pretty sure you will need to relocate to a stout front mounted intercooler for this amount of heat.

[@5uprnva]

I can’t see how an air to water Intercooler can heat soak unless there is a major issue with the heat exchangers.

[@cali_cal]

on stock flash too. I think its the intercooler or fan

[@petbull7038]

I don't know much about cars but I learn a lot from your channel. Keep up the great work

[@laskalives]

Intercoolers are either heat soaking because of their placement or they're not rated to be efficient with the larger turbos. Simple way to test it would be to wrap the body of the intercoolers with heat reflective tape and recheck, otherwise the intercoolers are too small.

[@rustler08]

That doesn't make sense because the issue is happening even at idle. We're not talking about a massive turbo change, thus there's no way they're making enough heat at idle to overwhelm what is actually a relatively robust system.

[@jasonschreiber6458]

Larger turbos create less heat compressing at the same boost level. (Stock tune)

[@philbert006]

​@@jasonschreiber6458not just larger, but way more efficient hybrid turbos. It's not the intercoolers. Likely just too many heat exchangers up front. Excessive interference by engineers is my guess.

[@laskalives]

@@rustler08 Yes because of heat soak. Do you think he gave a crap about IAT's before he started having an issue?

[@laskalives]

@@jasonschreiber6458 In theory yes but when we're talking about an increase in volume and velocity in regards to the application, no. I understand what you and the others are saying but I work in the field of thermodynamics.

[@DIY-V12]

This car is one hell of a gumption trap but now that you are this deep into it the problem is logically closer to being discovered and your methodical intelligent approach is surely going to win in the end. Will thouroughly enjoy the victory dyno pull video, keep at it and best of luck!

[@mandelbrotset7322]

Get a resistor and make the IAT static. Possibly a resistance high enough to keep the intercooler pump running . Do a couple pulls and then check Temps with the IR thermometer. It could possibly help determine whether it's a logic/pcm/harness issue....or an actual mechanical issue

[@krisa817]

You could try flushing out the intercoolers and the heat exchanger. They might be partially clogged

[@amgtrnd2245]

It seems like a simple solution. Although I’ve never worked on a v12 Merc. It seems like you cooling system is inadequate for the extra power mods you added. Wrapping the intake tubes could help. Adding a larger heat exchanger, installing a heat killer chiller etc. that V12 creates a ton of heat and keeping it under control can be a real PITA. Good luck

[@483SGT]

Doesn't explain the temp never recovering tho

[@amgtrnd2245]

@@483SGT heat soaked possibly? Which is why I believe that the current cooling system is not adequate enough.

[@lakeminnetonkaoutdoors7532]

@@amgtrnd2245 NOPE CL HAS ALL STOCK COOLING, ALLTHOUGH i DID MAKE A COWL UNDUCTION FOR HOOD, BUT ITS THE PLUGS NOT BEING TORKED

[@RUFAZZ]

I am having the same issues with my W215 CL600, so this is helping me a TON!!!! Thank you!

[@mikeresnik]

i have a thought, since your are running bigger turbos with more boost that means that the charge air will be hotter because of having more pressure, i think you have reached the thermal capacity for the stock cooling loop which is why it doesn't come back down once it gets hot. i think the cooling loop for the intercooler need to be expanded to hold more coolant and possibly a higher volume pump, add in another small radiator to the system with an electric cooling fan on it.

[@chipjones4194]

Agree!

[@williamghiatis6739]

Bingo!

[@yellowdogparty]

Some cars just like to be a hassle. I can’t offer tips for this one, but a lot of good ideas are in the comments. Hopefully you get it working soon! And thanks for showing us the whole process, even when you fail. We’ve all been there. Remember, it’s always the last thing you try!

[@aggiediesel9565]

Many have mentioned the EGR, I agree that would be a massive source of extra heat into the intake if it's not sealing up when it's supposed to. But first verify that the IAT Sensor is actually correct by sticking a thermocouple probe for your multimeter down the hole and see if it's really that hot down in the intake. Then slip it in your "Y" pipe in front of the throttle plate and see what's coming out of the ICs. And just because the computer is saying that IAT sensor is reading something doesn't mean that there's not a wiring problem between the IAT and the computer that could be affecting the signal.

[@Danishhodler]

Could it just be a egr related problem, with slightly opened valve or sticking valve, and what you see is recirculated exhaust gasses causing the intake temp to be too high? You could check it by the mass airflow sensor with your scantool.

[@jgibbs5118]

I wonder about that temperature sensor, if the sensor on your other blown m-b is similar try inserting the CLs sensor in that engine to see if it has any effect. Also you can check the resistance of the sensor from the other car whilst it is out. Personally I'd check the sensor resistance by immersing it in water and heat it up to boling and check out the change in resistance. Finally I'd rig some sort of connecting wire onto the sensor and use croc clips so there's no doubt about continuity to your meter. Mechanically everything appears sound so I keep coming back to the electronics, is it possible that the ECU has been corrupted? Can you borrow a proven one to check it out? Have you checked the IAT with a separate thermometer to ascertain if the sensor is actually providing valid information to the ECU. As you can tell I'm happy with the nuts and bolts and trust them I don't trust electrons.

[@NDPhotonl]

I'm also thinking in this direction as I also believe the rest of the hardware around this issue is probably fine. Try the E55 AMG IAT sensor, it looks identical (I drive a CLS55 AMG)

[@davidwengert4262]

I used to be a tech for VW during the V10 TDI Touareg days. I have had my clock cleaned so many times but it’s always a learning experience. It’s very hard to see that in the moment and not be frustrated or feel like giving up. Great video’s always love watching and feel your pain! You’ll figure it out at least your not flat rate anymore🎉

[@ktapani4893]

How much do you think this service would have cost at an official Mercedes Dealer Garage .