040mercedes

I'm having some issues with my c class. Here goes,

1. When I am getting ready to take off quickly, I frequently here a loud clunk from the underside more toward the back of my car as I first hit the gas pedal. I thought it was something in my trunk, but that's not it. Sometimes, during acceleration it will clunk and hesitate for a brief second then continue to accelerate. Possibly differential issues????

2. Every once in a while, it will run like absolute ****. It sputters and stumbles at a very low idle. It also has an extremely rich exhaust smell. Almost feels like it's getting ready to stall. When you accelerate, it chugs and struggles to gain speed. No check engine lights. If I shut it off, wait maybe 30 seconds and start it up again, it's fine.

Any suggestions?

69chevelle

I hear a clunking noise on my car when i put it in reverse only. Almost like the air conditioning is kicking in but I dont have it on. It only happens sometimes.

As for your sputtering problem, I would take it in for a tune up

040mercedes

bump

13benz

problem #1 i have noticed that on the back of the driveshaft in my c-class there is a rubber circle that attaches the driveshaft to the differential instead of a u-joint. mine is a 4 cylinder but yours may be a real u-joint, either way could that be wore out or broke?

Problem #2 Maybe a dirty air filter? dont know if these cars have a choke or not but could the throttle body be sticking?

good luck

michakaveli

My C220 has that clunk as well, worse when you put it in reverse completely stopped but with the foot off the pedal. Not bad at all whenthe foot is still on the pedal though.

The round item that connects the drive shaft to the rear differential you are refering too is teh flex-disc. Supposedly the flex-disc on mine was replaced

The car itself is also not as steady at idle either. The RPMs fluctuate slightly at idle. But then again it's a gasoline engine, I'm used to my diesel though that runs like a clock.

GDawgC220

sputtering, feeling like it's going to stall usually associates with the Mass Airflow Sensor. If you haven't had that changed yet, it may be time. How many miles are on the car?

As for the clunk, is it when you shift into gear or are you at a stop light and happens when you start going?

040mercedes

Lets see...the car has about 126k. The MAS sounds logical but if it went bad wouldn't it still throw a check engine light?

As for the clunk, it doesn't do it when I put the car in drive or reverse, and it does not do it when the transmission is shifting gears. If the car is in drive and I am at a standstill, like a stop sign or traffic light, this is what happens, I give the car a substantial amount of gas (not flooring it) it clunks just before take off. Occasionally it will clunk and hesitate during acceleration in first gear, NOT during the shift then proceed to accelerate. I thought maybe it could be something as simple as an item in the trunk moving around, but I've checked and that's not it.

A bad flex joint would be a pretty good place to start. I had the same problem on my 190e except there was no loud clunk. Just a very noticable vibration.

michakaveli

Mine does it when shifting into gear from park. Nothing when already in gear at a stoplight.