Need help with my rough engine
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Joined: May 2010
Posts: 4
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c230k
Need help with my rough engine
I have a 99 c230K. It has 170,000 miles. It idles rough, surges a tad at idle, and runs rough at any rpm.
Currently, It starts fine, and accelerates fine, but the rough engine is noticeable. GAs milage is suffering too. It is showing P0170.
Here is a little history: Over the summer, it didn't want to accelerate fast. Press the gas, and it sputtered and hesitated. I replaced all the plugs, and it ran like new. BTW, the plug well closest to the fire wall was full of oil. covered a third of the plug. A few weeks later, it started running rough, and didnt want to accelarate at all! Check engine light on with lots of codes. Ran worse than before. I ran 3 bottles of injector cleaner, and it helped a lot. Now, it just runs rough. Here is what I have done since the injector cleaner:
-PLug wires
-Coils
-new fuel filter
-clean the MAF element with MAF cleaner.
None of this seemed to help. I have read it could be the MAF or O2 sensors. I don't want to keep throwing parts at it. I peered around for a loose hose, but none were evident. What now? oil residue in cables? Bad compression? Any help would be great.
Currently, It starts fine, and accelerates fine, but the rough engine is noticeable. GAs milage is suffering too. It is showing P0170.
Here is a little history: Over the summer, it didn't want to accelerate fast. Press the gas, and it sputtered and hesitated. I replaced all the plugs, and it ran like new. BTW, the plug well closest to the fire wall was full of oil. covered a third of the plug. A few weeks later, it started running rough, and didnt want to accelarate at all! Check engine light on with lots of codes. Ran worse than before. I ran 3 bottles of injector cleaner, and it helped a lot. Now, it just runs rough. Here is what I have done since the injector cleaner:
-PLug wires
-Coils
-new fuel filter
-clean the MAF element with MAF cleaner.
None of this seemed to help. I have read it could be the MAF or O2 sensors. I don't want to keep throwing parts at it. I peered around for a loose hose, but none were evident. What now? oil residue in cables? Bad compression? Any help would be great.
Thread Starter
Newbie
Joined: May 2010
Posts: 4
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c230k
update
I tee'd in a vacuum gauge this weekend. It fluctuated between 19 and 18 inches. It would hold each point for a couple seconds. Did it consistently. Is this a vacuum leak, or a valve in the vacuum circuit not operating right? Or could it still be the MAF?
ammendment: I just remembered that the last time I had the car in, the mechanic said I had a small head gasket leak. Could that be the culprit?
ammendment: I just remembered that the last time I had the car in, the mechanic said I had a small head gasket leak. Could that be the culprit?
Last edited by Arcticfox35; Jan 15, 2011 at 03:28 PM.
Thread Starter
Newbie
Joined: May 2010
Posts: 4
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c230k
problem solved!!!
I took my car to a small shop that does German cars. The problem, bad motor mounts!!!!! They replaced the Motor and tranny mounts for $600. Car runs right now. I NEVER would have guessed that. Hope this help somebody.
Member
Joined: Mar 2008
Posts: 96
Likes: 3
Mercedes Benz c230
I thought that might be the issue, but ouch $600 for mounts. I'm thinking this might be my last benz.
I experienced rough engine right before idle. I still have no idea what happened and why it's pretty much gone but I've done the following. Again, I have no idea whether any of which of these contributed to helping my situation:
1. Changed tires. Maybe they were on loose? Probably not, but some people have thought that maybe that might've been the issue since the cars get rough just before stop.
2. Changed alternator
3. Changed spark plugs. It might've been the plugs b/c even after I changed the alternator it was still rough.
Again I'm not a gearhead. Just thought I'd post in case this helps someone or someone can make some sense out of it. Good luck.
I experienced rough engine right before idle. I still have no idea what happened and why it's pretty much gone but I've done the following. Again, I have no idea whether any of which of these contributed to helping my situation:
1. Changed tires. Maybe they were on loose? Probably not, but some people have thought that maybe that might've been the issue since the cars get rough just before stop.
2. Changed alternator
3. Changed spark plugs. It might've been the plugs b/c even after I changed the alternator it was still rough.
Again I'm not a gearhead. Just thought I'd post in case this helps someone or someone can make some sense out of it. Good luck.
