pointman

04 c32.
about 40k.

Strange... when at a dead stop, and give pretty good acceleration (but nowhere near full throttle) the car takes off fine, but then right at about 2800 rpm the car thuds and trips the traction control light. It doesn't feel like the rear is breaking loose. It feels almost like the car is shifting into second, and the gear change is really hard. However, it is happening in first.. cause I tried just staying on it, and I was able to go higher in the rpm range without issue in first. Only happens when I push the car semi hard. Think of it as when you are in a two lane road that merges into one lane.. you want to be first, but don't need to go all out.

I did a search and many seem to have a similar experience at 1500 rpm being glycol contamination. Is this what I should be looking at as well? Any thoughts appreciated. Thanks.

SilverBulletAMG

Have you tried taking off in "W" just to see what it does? Tried the ole adaptation reset trick?

pointman

Didn't try W, but did the adaptation thing. No difference.

msheredy

It's the supercharger's clutch engaging. Typical for these cars, and others with the same engine.

SilverBulletAMG

I can hear when my SC engages but I never "feel" it engage. There shouldn't be a jerk from that.

pointman

I've owned my C32 since new. I have never once had this happen.

msheredy

Clutches, like everything else, show signs of wear as time goes on. Some owners feel it others don't. When you feel this jerk, do you sometimes hear a slight churp by chance?

I'm used to it on my car. I can actually feel, at low RPMs, when the blower engages as it actually strains the engine a bit till the boost picks up. Kinda nutty but that makes sense since it takes power to make power with a blower.

pointman

No, no chirp. This can't be normal it is far too rough a feeling.

320 dreamer

s/c actually engages below 1200 rpm. if you raise the hood and have someone watch the clutch then raise the rpm they will see it engage.
sounds like a tranny issue. try a filter swap and fluid flush

pointman

Thanks for the input. Had trans filter and fluid done maybe 5k ago.

msheredy

The supercharger can engage as soon as 1200 but won't, if it doesn't need to, till approx 2,800 RPM—after that point the ecu turns on and keeps it on till you let off the throttle for an extended period of time. It all depends on the engine load.

I know, sometimes my car feels like I'm popping a clutch as if I had a manual gearbox. Sometimes it's just a slight blip. Do you know anyone else who has a C32 or even an SLK32? Drive their car the same way and I betcha you'll feel it.

60n5pt1

Do you have any mods? could also be belt slippage.

FrankW

I'll agree with msheredy here. sounds like it could be the s/c clutch slip.

pointman

Weird. It comes and goes. Some days nothing.. then it comes back another. If its the clutch, its normal?

FrankW

hard to tell if it's belt slip causing the jerk or clutch slip. if the clutch physically looks fine I would change the belt and see what happens. It also may be the belt tensioner if it's the belt slip.

c32AMG-DTM

Agree with Frank. Change the belt for a new OEM one - pretty cheap "fix" ~$60 or so IIRC. If that doesn't work, maybe it's the tensioner. If you replace both and it still exists, it's probably the S/C clutch... not sure what options exist (if any) to address that on a C32.

ScottW911

pointman,

I don't know how much help this will be but, I have the exact same issue, intermittently. Here was the thread I started on this issue:

https://mbworld.org/forums/c32-amg-c...hirp-saga.html

Try Jerry's suggestion to disconnect the S/C to determine if it is, in fact, the clutch. It takes 30 seconds to diagnose it with his suggestion.

I purchased a spare S/C for less than a new clutch assembly would have run. I am keeping it at the ready for when the clutch does give up the ghost or it becomes so annoying I can't stand it any more.

msheredy

Good idea! Let us know what happens Pointman.

pointman

Thanks a ton guys! Appreciate the link! Gonna read it now. I can't wrench to save my life. But I am gonna do some searching and hopefully come up with something. Will report back if I figure anything new out, including a resolution.

320 dreamer

check out woody's thread on this issue. he shows were the s/c comes on at approx 1200 and stays engaged until under the same rpm. for all intensive purposes the s/c stays engaged while driving.
i have a slk32 and have never experienced this in my car. its a smooth as silk and when stomped on the power is instant.

msheredy

I know which thread you are talking about. You are missing the point though. Do you drive your car with your foot on the brake? I don't. What he demonstrates is that under a load (i.e. foot on the brake) that the ECU wants to turn the blower on. If you pu$$y foot the throttle from a dead stop with the tranny in first you can get to ~2,800 RPM before the blower engages. Since you car's clutch operates smoother you may not feel this.

320 dreamer

i dont drive with my foot on the brake. but with the car in gear it will be under a load. not sure how to *****foot the car from idle to 2800 rpm im not feeling any jerking . i will try a few different styles of driving and see what happens.

ScottW911

No wrenching needed. Just put your thumb on one side of the clip and your index finger on the other side. Now, apply inward pressure between the thumb and index finger while gently pulling the clip away from the main plug.

Test drive.

Reverse process, utilizing thumb and index finger.

pointman

haha pwnd. Thanks.

djoa

I have similar case when I bought mine, I think there was the nightmare coming. So I change the new water tank (update version of Valeo from deler), change the gear box oil. The jerk still always shows up, esp when launch the car w/o traction control warning at all. Other than jerk, the fuel consumption in city was extremely high becuase the tranmission control unit ordered the torque convertor to unlock and shifted to higher gear.

Last week, I have the tranmission control unit reset and everything back to normal. You can try this first before glycol test