Hello all,

My 96 C220 has begun to stumble at higher rpm (>3800) and then hold the gear almost to redline unless I back off for a fraction of a sec, then upshifts.

The stumbling is not unlike the rpm limiter kicking in when reving up to 4000 in park.

I just replaced the MAS tonight and drove it a few miles, but the symptoms remain.

The car has 121k miles and I had the idle control valve replaced about 3k miles ago.

Any suggestions would be appreciated!

You could try disconnecting the battery for a few minutes & making the computer re-learn.
Even so, it will probably take a little drivingtime to re-adapt proper fuel values.

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2007 C 230 Sport.

I'm hoping that just having the computer adapt is all it is. I'm just afraid that it might be more.

re- adaption does not cause misfires....have you pulled the codes yet?

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__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

if there is misfire...there will be P0300 series codes.

__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

I haven't pulled the codes yet. The CEL never came on either.

Emission related codes may not set CEL....need cleared for good drivability.
Common problems are...Wiring loom engine bay....Flywheel sensor....Ignition components breakdown.....Over Voltage Protection Relay.

Before you change OVPR, do a check on charge voltage...max is 14.6vdc.


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__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Thanks a bunch for your responses!

I drove it to the office today. It stumbled a little bit around 4k and/or around 5k. I went out to lunch today and pulling out of the parking lot, I couldn't get the rpms over 1500. I turned it off and restarted it. It then seemed ok.

I won't be able to do much diagnosis until later this week. I'm hoping to avoid a trip to my mechanic, but it's not looking good as I only have a primitive code reader.

I noticed it idling somewhat roughly this morning (air temp 27 F, -3 C).

Hiya guys, found this website when looking for a couple of solutions to various issues with my W210. I had what sounds like the same thing recently, the gears would occasionally slip and it was taking an age to change gears from one to the next.

It was making me crazy but I have just had the car back from a Merc Specialist here (I'm in the U.K!!) and it was due to a leaky seal in the gearbox (I'll find out the exact solution). Apparently it's a common issue with automatic Mercs and the part was only a few quid (£'s). All right as rain now, changing gears with ease every time.

If the gears aren't changing up or down when they should or are just simply failing to engage at all, then it could be down to the reduced oil pressure caused by leaking oil in the gearbox. Get the gearbox dipped and I think you'll find that it's low, get it sorted soon though as otherwise it'll burn out your gearbox!!!

It cost me £90 including parts, oil and labour so not a big job but it would have cost me £3000 if the gearbox had burnt out!!!

I'll pm you this too to make sure you get it!!!.