RobKellz

Hi, I'm relatively new to the board and haven't really posted much, just looked around and read a few of the DIYs. I am currently in Gulf Breeze, Florida and recently bought my girlfriend a 2005 C230 Kompressor with 75K miles. Every now and then when the car comes to a stop it will stumble and the idle rpms will begin surging.

I have replaced the idler pulley, MAF, and the tube going from the air box to the valve cover. None of them have had any effect of the surging so I'm posting to look for more ideas. I have read several threads on this and many of them seem to go dead without anyone posting a response so I'm trying here myself.

Things I have researched and plan to try next if I don't get answers are the belt tensioner pulley and the engine and transmission mounts. I have also heard that it may be the air filter not seating properly against the MAF. I have reseated it a couple of times without any success.

Any thoughts from you guys??

***UPDATE***
I just made an appointment at the Mercedes dealership to accomplish the cam sensor open campaign. Hopefully this fixes the problem or at least turns something up...

jreC230

I had the same issue on my coupe. mine was a misfire on cylinder 4.... changed out the coils and problem solved. Also keep in mind the "voltage regulator" on the alternator.

RobKellz

Did your do it every time or just intermittently? Some days it shakes and surges really bad when I push the brake and come to a stop, other days it doesn't do it at all. Also, I'm not receiving any misfire codes. The only code I have gotten is the P0171 too lean bank 1.

jreC230

thats how it started at first then it moved on to a daily thing and really annoying.... id come to a stop and have my foot on both brake and gas to have some idle just to it wouldnt shake or act like it was going to shut off. I also had a gas leak at the same time (the sending unit broke off and was leaking gas). Best thing id suggest is have someone with the star diagnose it. they can give you a better read.

jtwillia2

For me this ultimately ended up being my alternator not working properly. At first it was an occasional thing like you describe and gradually increased to where it was every day at every stoplight. A shop should be able to test your alternator to see if the voltage is spiking/dropping, which is what mine was doing. It could be the voltage regulator attached to the alternator, but if you do the replacement yourself you'll have to remove the alternator to get to the voltage regulator anyway.

Something to try first would be to thoroughly clean your throttle body (including the internals), which I described in a thread here, and the hose connected to it. If there is even a tiny amount of oil residue (there usually is on mine) it can cause weird throttle issues. I now do this with every oil change.

RobKellz

I just had the recall done and the idle surging and shaking still continues. I went ahead and broke down the airbox again and re-checked all the seals and hoses but didn't find anything out of the norm. I don't want to pay the stealership $150 for a diagnosis that won't turn anything up because the problem is hard to replicate due to it only happening once every now and then.

RobKellz

I'll go ahead and give cleaning the throttle body a try sometime this week then report back. The alternator looks brand new so I don't believe it is that but I'll get it tested. Thanks!

RobKellz

Just to add an update. I'm still getting the vibrations and they come more often while the AC is on and the car is stopped in D or R. Additionally, I just got the p0410 code

Opelveve

same problem here ,,,did u solve it ????

Opelveve

getting the vibrations and they come more often while the AC is on and the car is stopped in D or R

did u solve it?????????!!!!!!!!!!!!!!!!!!!!!!!

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RobKellz

Hey guys, I ended up buying a new o2 sensor because the check engine light came on and my scanner was showing the car running in closed loop. I reset the check engine light and after about 10 miles of driving it keeps coming back with the p0171 and p0410. Any thoughts? Also, I notice if I have the AC on the surging starts to happen more often. Additionally, if I turn the wheel while stationary and in drive, the surging starts while the wheel is turning. I'm thinking it may be my belt tensioner pulley so I ordered that also. I'm hoping I can fix this soon because this car has got to be the most problematic vehicle I've ever owned...

RubyCarbon

moving my post to a different area.

wvadam

A code for 'too lean' is often a dead giveaway for a vacuum leak somewhere. google how to find vacuum leaks or take to an independent mechanic to diagnose. It is easy for them to do. You will spend way more money fixing parts that are not broken.

Russell Ormerod

Self diagnostic because you don't want to pay for a professional diagnosis makes no sense already you have spent money for nothing. And if you think a belt tensioner will fix a surging issue... well good luck on that one.. one tip I will give you. Vacuum leaks. Pressurise the intake system and check for leaks. Cleaning the throttle body now that's a step in the right direction for sure. Btw. Is she still your girlfriend? Lol. Good luck fixing

Killa' Benz

Did you ever get this fixed?