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C43 stumbles at idle/ cuts off rarely/ smoke

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Old Nov 5, 2009 | 12:32 AM
  #1  
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From: Newport News
1998 C43 AMG, 95 Acura GSR , 97 Civic Hatch
Exclamation C43 stumbles at idle/ cuts off rarely/ smoke

Hello! thanks for your help. my 98 C43 has 80k miles and in excelent condition. I do not drive often, a few times a week maybe. After sitting for a few days, when I start it , a puff of light colored smoke comes out for the first few seconds. Its not burning or consuming oil, so I dont think its a head gasket, plus it doesnt smoke under acceleration or any time after the first few seconds. Also at idle 6-700 rpms, the car has shut off on me twice in the last month. Just kinda died, but started right back up. And normally RUNS GREAT....I am by no means a pro, but I have noticed a small valve cover leak. Is it possible that after sitting, the oil leakes from the valve cover into the timing cover or somewhere and is burning off? I am concerned. Thanks
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Old Nov 6, 2009 | 02:09 AM
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190D 2.5 (x2), 190E 2.6, W202 C240,W202 C43 (C55), W210 E55, W212 E250CDI
The smoke on cold startup is normal, all AMG's do it every now and then (not every time though).

The stalling is probably a bad AMM/MAF, does it feel like it has poor performance above 4000rpm?
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Old Nov 6, 2009 | 09:49 AM
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From: Newport News
1998 C43 AMG, 95 Acura GSR , 97 Civic Hatch
The smoke is only on cold startup..But thats normal? (its just a lil) I worry alot.. And the car seems to run fine at all rpms.. I am using K&N filters that were in the car when I bought it.. Should I change to MB paper? THANK YOU
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Old Nov 6, 2009 | 09:34 PM
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Valve cover leaks are common with ours cars.The shutting off of the motor could be the beginning of the CPS - crank position sensor going bad.
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Old Nov 6, 2009 | 10:17 PM
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From: Newport News
1998 C43 AMG, 95 Acura GSR , 97 Civic Hatch
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Originally Posted by C43AMG
Valve cover leaks are common with ours cars.The shutting off of the motor could be the beginning of the CPS - crank position sensor going bad.
Thanks Have you changed yours(cps) before? Where is it located? And I bought new Valve cover gaskets, how hard are they? I am an experienced mechanic, but I like to ask questions when im unfamiliar. No special tools needed? Probally silly questions, but.. Thanks for the help
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Old Nov 6, 2009 | 10:18 PM
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From: Newport News
1998 C43 AMG, 95 Acura GSR , 97 Civic Hatch
Thoughts on paper filters vs K&N?
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Old Nov 7, 2009 | 12:11 AM
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Originally Posted by tonysemi
Thanks Have you changed yours(cps) before? Where is it located? And I bought new Valve cover gaskets, how hard are they? I am an experienced mechanic, but I like to ask questions when im unfamiliar. No special tools needed? Probally silly questions, but.. Thanks for the help
Ihad mine changed by my mechanic about 2 years ago as a preventative measure.It's located along the firewall underneath the mass airsensor area.It took my mechanic about 15 minutes to change it out.
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Old Nov 7, 2009 | 12:22 AM
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Originally Posted by tonysemi
Thoughts on paper filters vs K&N?
I have had K&N in everything I've owned.The primary tradeoff is filtration for increased airflow.I am willing to make that trade.I suggest you go to K&N's website for their statement in relation to their filters and them being blamed for mass air sensor failures.The biggest problem I see is when the filters are cleaned for the first time.They are over oiled and immediately placed back into the vehicle followed by aggressive driving and or reving of the motor.I follow the directions provided , allow it a hour or two to dry after re-oiling , then return them to the vehicle and let the motor idle for about 5 minutes to draw additional air over the filter surface.I then normally have the car sit overnight and resume normal driving the following day..I have never had any issues with K&N'S causing problems with my vehicles.
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Old Nov 7, 2009 | 07:00 AM
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The rocker covers is an easy job, no special tools. Do a search, it's been covered many times. Make sure the breathers are clear when you have the covers off.

Intermitant stalling and no restart for a short period is usually a CPS. Stalling and an immediate restart is usually something else such as an air leak, dirty throttle body, blocked breathers, bad AMM/MAF.

As for air filters, either paper or K&N are fine. The K&N oil won't damage the AMM/MAF like many people think it will. I prefer paper, but that's a personal choice.
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Old Nov 7, 2009 | 10:23 AM
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From: Newport News
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GOOD INFO guys! Thanks. I am aware of the proper cleaning procedure of the K&N, so I will definately make sure the filters are dry. Cleaning at night is a good suggestion as far as alowing time to dry. As far as the rocker cover/valve cover, I will search it to get a better idea of the procedure. One last question... parts.. OEM or aftermarket? I.E. CPS or gaskets?
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Old Nov 8, 2009 | 10:06 AM
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[QUOTE=tonysemi;3800496One last question... parts.. OEM or aftermarket? I.E. CPS or gaskets?[/QUOTE]

OEM , thats all your going to find for the parts you need to replace anyway.
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