mrgoodcat66

yeah thats a real shocker....

slowsky

so after several weeks, symptoms are narrowed down to when the weather is cold, the engine/car vibrates more in park....when the weather is hot/humid, vibration is minimal in park...

could the fuel/air mixture be off when cold? pulling too much air since cold air is denser? no idea where i'm going with this theory...

Johnpidge

Ok I'm late joining this thread but my 208 clk55 does much the same in park usually when cold start or when hot idling (i.e. in traffic) slightly - these sort of things annoy me too. I've not changed plugs or leads yet but fitted new MAF sensor, air filters, belts, all oils, engine and gearbox mounts but have a little clonking noise going on when off and on the gas in stop start traffic - guess thats the flex joints??

The plugs should have been changed prior to me owning the car ish 18 months ago (probably 5000 miles)

I've run fuel injector cleaner a few times which seems to have helped but you have gone the full 9 yards. Yet to check the O2 sensor or the CSS but need to get some money together for a plug and lead change at some point. Goes perfect in every way otherwise. Found it surged once or twice when I was really really going for it (130mph ++ on a private airfield don't panic but it was very hot 32º c for the UK) but run 97+ RON Europe or Optimax 99 when I can get it. Driving me a little mad as well

slowsky

the worst part? No check engine light or stored codes...

Really frustrating and nobody seems to know what's going on, even star diagnostics. Star reports everything is running at optimal levels except for brief flashes of possible misfires when running smooth engine diagnostics.

Mechanic said possibly dirty fuel rail but not enough to trigger misfire codes. AMG engines are very sensitive and *****y. Hmmm, reminds me of certain species

doberzus

My clk55 does the SAME thing!....ONLY in Park does it "shake and vibrate" but its silky smooth in all other gears, everything is perfectly fine>>>even when im stopped at lights its smooth...i just always thought that maybe its normal....now its got me a little worried.....but im sure everythings okay it doesnt bother me think i can live with it i love my clk!!....good luck man

slowsky

doberzrus: i've been tracking and dragging the car despite the idle issue and according to star, everything is still running fine...

despite the issue, i still went ahead and modded the car with renntech air box and deleted my secondary cats/resonator...next in line are ams headers and tune to tie it together...

doberzus

yeah i mean i heard alot of people with the same issue on e55 AND clk55's i think for how powerful these engines are being 8 or so years old,i came to the conclusion not to worry about it, its normal since all your tests show everything is fine sounds good though i need mods on mine asap loll...goodluck with your monster!!

slowsky

I just ordered crank position sensor, camshaft sensor, and a coil pack. As soon as I find out if any of this works, I will let you know.

Johnpidge

Camshaft sensor?? I can see a coil pack helping - but usually when a camshaft sensor goes (did several time on my old WRX Subaru!!) the car goes into limp home mode and won't rev at all - coil packs usually give misfire at higher revs (like my old TT Soarer)

Let us know how you get on!!

slowsky

i have no misfires or cel...i'm just replacing things since they will need to be replaced anyways...hopefully i can solve my problem in the process. Absoutely no one has a clue why my car is behaving the way it does. Yet I still have full power and no issues as a daily + track car.

doberzus

Hopefully that will help, but im still convinced its normal, even though sometimes i think it's not. On my 55 it's minor and it does it in Park ONLY, other than that the car is a beast!! I have heard of a lot of people on both CLK55's AND E55's (W208/W210) complain about "wierd vibrate,shake, and shiver" and ALL of there cars are running in tip top shape, and there is absolutly NOTHING wrong with them. Maybe these torquey,powerfull engines just shake a little when there 8-10 years old but then again not everyone has these symptoms....i dont know lol

onlinealias

You said that the #4 cylinder was iffy. The only thing that can cause a single cylinder to do something different than the others is the spark and the injectors. You have replaced the spark plugs/wires twice, so it is the injector. Perhaps I missed it, but did you replace that injector?

A full missfire is detected by the CPS circuit...if there is a fluctuation in RPM that is synchronized to a particular degree of rotation the CEL will mark the offending cylinder as a misfire. If you have RPM variation at random, then it will throw a 300 'random'. Unfortunately you have neither, so you are going to have to look between the lines. If you have a slight missfire with a bad injector then what I would look for is one of the banks to go rich/lean. This would indicate that the injector is stuck open, or stuck closed. I'd check to see if the readings that are coming off the O2's are the same as one another, and go with the one that is farther out of range. This will narrow it to the bank...if that bank matches #4, viola, it is the injector.

slowsky

Onlinealias: thanks for the suggestions...I replaced the upstream o2 sensors and the shivering went away in drive but not in park...I have ran 3 cans of seafoam and one can of techron through the gas tank within the last 1000 miles...we have monitored the o2s and they all perform good with an occassion lazy dip from the rear left bank o2...not enough to trigger constant shivering while in park...it seems like underload its smooth but off load in park and neutral it shivers like crazy...in cold weather its worse...when hot out sometimes the idle is smooth in park, neutral, and drive...possessed? Think I need an excoricst..

slowsky

o and 4 was an issue prior to the o2s...now the smooth engine diagnostics states its bouncing between all cylinders...took off the maf and same issue...could fuel rail be too dirty?

onlinealias

I'd try thinking of it a different way. The o2 sensors aren't the culprit. They are your tool to diagnose what is going on. The ranges that they are operating in is key...their actual values. Try to narrow something down associated with the left or right bank. (before cat, the after cats only tell the compute that the cats themselves are working).

If you can't get it nailed down that way, then you might want to try to find one of those hard core electronic engine analyzer guys, the ones that can look at all of the sensor data and their relationships to come to a conclusion. Nothing gets by a guy that is really good at that.

slowsky

Ah ok...I will monitor it with my mech, he is quite baffled and never seen a problem he can't solve...I tried everything to get the cel to pop...multiple track runs pulling high 13.4s which isn't too far from amateuer drag...so power is there, I just have horrible reaction time...

onlinealias

If the fuel rail was dirty the pressure would drop, causing 02 to show lean range.

slowsky

o, fuel rail pressure is fine then, did see tiny specs of dirt when we took a sample...but pressure was good...i'll take your suggestion and monitor the o2s...will be back to report in couple weeks...

slowsky

after several attempts at fixing, I think I've finally found the culprit. After replacing the crank position sensor, things went back to normal. My idle isn't glass smooth but the car does have 100k miles on it...the rough idling is gone.

Not sure if replacing just about everything helped but the last straw was the crank position sensor. After couple of weeks of smooth idle in park, I replaced the cam position sensor and cylinder 4 coil pack. Didn't improve the idle but the rough idle also didn't come back.

Figure I would replace one coil pack a month just for maintanence.

Thanks for everyone's suggestions/advice. Great community we have here!

desired_speeds

I have the same problem as you and I ended up replacing the CPS today. Unfortunately same results. did you manage to get any farther in your diagnostics?