Greetings. May i please request direction/help. 2002 C32. Original owner. 77k on the odometer. Off warranty now. MB Manhattan vehicle. Check engine light came on. Changed plugs, coils, air & oil filters, wires, fuel injectors, injector seals, lower & upper seals on oil cooler and filter housing, valve cover gaskets, oil etc. Engine still shaking at times. No compression lose or vaccum leaks/lose. Wondering, can a faulty valve spring cause this problem before returning to mechanic or should I suggest that he diagnose something else...?
Thank you in advance... Haledon NJ

Any codes?

didn't early c32s had problems with cams.

I'm having the same problem lately, I'm getting codes for cylinder misfires all on the right side. going to try and change plugs to start

yes... said cylinder six then one time cylinder three.

Let's hope it's not the cams. Short of taking almost the whole engine apart, it would be hard to know. If you are lucky, it's the wires or the plugs. Also being cylinder 3 and 6, it may be the cats since 3 and 6 are near the cats and may be affected by cats that are going (or gone) bad. I think that was Jake's problem.

hello,

i have the same problem, result of the fault location -> pre cat fail.

What codes did you get?

Had several cylinder misfires, replaced plugs and coil overs, replaced Crank positioning sensor, ended up being a leaky intercooler that was sending coolant into the intake. replaced my intercooler and all probelms went away.

Thank you, everyone, for advice and direction. Changed plugs, wires, coils, fuel injectors. Will ask mechanic to examine intercooler for leakage, check codes for cats. It was stated no compresiion lost and no vaccumm leaks but will ask to perform tests again. Please. keep the advise coming. Again, thank you all.

The easiest way to check is remove the AMG plenums and see if there is coolant build up. that will tell you if your IC is faulty

I think this is an issue with these cars. I've been having the same issue. Ton of parts just arrived at my house today. Plan to replace head gasket, plugs, filters and one thing that wasn't on your list, fuel filter. I'll report back if it helps. I've yet to throw any codes though.

I will also say that if your coolant level is not dropping then your problem is probably not the same as mine.

So I have been having some misfires of late and found this post.

My CEL has come on and is showing misfires on cylinders 5/4/3 and also showing a P0456 (emissions leak). The issue has been coming and going and the CEL light will stay on for a few days and then go away. I thought I could pop the light by a few WOT runs on the freeway. This did not work. I did this as I thought it might be my intercooler pump. Most recently the CEL comes back on with just normal acceleration to a freeway on ramp. Once the issue hits, the call will run 'ok' but stutters a bit and gets much shakier than normal. If I turn the car off and then back on again, the stutter goes away.

I thought it might be the plugs.. so after 120K miles the old plugs were due for replacement and the car would be better with a new full set of iridiums. So I have all new plugs now. Wondering if I might have tweaked a coil wire. I probably should just do new ones for good measure. How does a coil wire wear out anyway? Just the connections and such?


I am still getting the misfires and am wondering... how and where would I check for coolant build up on the plenums? I 'have' had to add coolant several times over the summer. A plenum is the air intake boxes yes? Where my K&N filters are... is that where I am looking for some sort of buildup? What does the build up look like.. are we talking oiling dirty gunk or will it simply be wet from coolant some how getting on the air filters?

Next question... how or why would coolant get into the air intake system on top of the engine? Sorry for the questions... I like to work on it, just don't get to tinker very often.

Where is the most likely area for the coolant to leak?

Thanks

Did you check yhe errors after replacing plugs?

Coolant in plenums is caused by leaking intercooler underneath the supercharger.
This can't cause misfire on 1 bank only! Problem is elsewere.

This is how it looks when you have intercooler leak:

Thanks for this info. I believe you are correct. I am getting all the gaskets together before taking it apart. Looks like needswings has a kit. Seems high at 189.. is it cheaper to source them individually? I have ordered the plenum gaskets from them at $20 but they have not arrived yet.

I get a misfire sometimes when I floor it. Just one valve or bank... just wondering if there was an update to what happened?

Check crank shaft position sensor, or can shaft position sensor,or ur plugs and wires

Really it could be any of the things that Morph suggested or a faulty injector among other things. What codes are you getting. What has been done to the car? What have you tried to do to fix it?

I have a LOT done to it tcu,ecu,intake amongst the big ones. I am thinking it is the CPS and or wires. since those are the cheapest I will start with them. everything else looks fine but have not checked plenum for gunk. My coolant looks clean and my misfire is in bank 5 only so I will start with that. It has been garaged for the last few months so it will be at least a few weeks (all the snow) before I get it out and running again thanks for your help guys I will keep you updated. Also you should joing the Mercedes C32 fb Page, we have a lot of discussions there. I am an admin so join up and I will approve ya.

Ryan