Q-Dog

Hello-
My '05 CL55 with 157,XXX miles has developed a very bothersome problem that my indy shop doesn't seem to be able to figure out.

At very low speeds 1st gear, 1st to 2nd gear, when I do a very low acceleration the car lurches (the acceleration stalls then re-accels several times). The indy shop has changed plugs, plug wires, injecters, lots of stuff to no avail. I have put new tires on it. It occurs with ESP on or off....seems like a super-charge thing...

Anyone have a clue, or do I need to take it to the dealer?

thanks ahead of time...

OCKlasse

Supercharger clutch?

stamper197

The problem I have with mine is the oposite.. the car just lurches foward with a lot of power and then uses normal power when accelerating at low speed. Its like when you were learning to drive a stick shift back in the day. Only does it when the engine is cold. So im guessing it must be some sort of 02 sensor or something like that dont know. Perhaps timing? dont know.. or tranny.. could be so many things.

biker349

possibly ignition transformer.

Q-Dog

an update:
my repair shop is telling me this is a transmission problem. They found gold metal flakes in the tranny so they changed filters and fluid which solved the problem for about 10 miles of test driving.

Sounds quite plausible to me (but what do I know). I think my next step is to take it to the dealer and have them check it out without telling them what the repair shop thinks.

alx

does it do it only when engine at operating temp?

Q-Dog

The problem occurs whether the engine is warmed up or not... I am pretty sure but I will verify that....

Why do you ask?

alx

because it could be your supercharger clutch disengaging as you run hot. and you run hot because your ic pump is dead.

just a hunch. i might be way off.

it could be your throttle blade motor/ throttle sensor, etc.

ideally you will have your car read. that would provide a starting point.

metal in atf is definitely not a good thing though anyway you view it.

Q-Dog

Good advice, thanks.

I have been thinking it could just as easily be a super-charger thing. However my mechanic states he is getting no failure codes.....

next stop will be the dealer for the 2nd opinion

alx

Is you tech reading the car with star?

MAD CL55

I don't think the Supercharger Clutch would throw a fault.

I would also suggest checking/replacing the supercharger clutch like ALX and OCKLASSE suggested. Hopefully it's something simple.

Q-Dog

I have done some testing on the warmed up engine vs not warmed up. The problem is barely detectable when the engine is 1st cranked up in the morning....It still lurches but it is barely detectable. Once warm it is a pronounced problem.

Also the problem doesn't really feel like a tranny thing (altough I am not an expert).

Speedriven1

There was an update at the dealer with a fix to a similar problem with software

AndreNY

does it feel like the supercharger is not engaged when the problem occurs? which means almost no power and a sluggish feel on the gas pedal?

Q-Dog

The lurching occurs very quickly, faster than gas pedal feel time. I would say the 1st iteration is about 250 msec (1/4 sec) no power then 1/4 sec some power, with the subsequent iterations each less than the previous until after 4 or 5 lurches the acceleration becomes normal. Characteristic of a hysteresis curve kinda thing.

JPhamily

Maybe change the fuel filter if that might help?

Q-Dog

an update:

I finally got tired of the lurching problem and have the car at the dealer. Their diagnosis was to 1st flush tranny and torque converter fluid and run it a 100 miles or so. But I have already done that by my independent shop. S they state the next step is to replace the torque converter.

My independent shop wanted to replace the tranny with a re-build and that would include a torque converter. I have opted for the torque converter only with the work done by the dealer since they have (apparently) sniffed out the problem.

So they are replacing the torque converter. I will not get the car back until Monday. I will update this thread after I pick up the car.......

kustom2k1

I've seen cars do what your describing due to a dirty throttle body. How does the car idle?

Q-Dog

It idles just fine.....

Q-Dog

The MBZ dealer has completed the work and it turns out the actual problem wasn't the torque converter, it was the Transmission valve body. Good because that was cheaper than a new torque converter (approx $2000 instead of $3000 in dealer $$$).

My independent shop had stated the problem was related to the tranny hydraulics. Nice that I didn't do a complete tranny to fix the valve body.

The only caveat is I haven't picked it up and driven it to prove...

Q-Dog

The problem is indeed fixed. My CL is now running really sweet. 160,000 miles and tight as a top.

JPhamily

My car is doing the same now and after reading this thread I think I have the same exactly problem as you. I'm about to hit 160k miles too... So what exactly did you have fix and how much did it cost you. Thanks