Hi everyone,

I have a 2008 Mercedes C350 (150k miles) and today while I was at a stop light my car started having some very slight hiccups. And it kept on doing it every time I would get to a complete stop. It's a small tremble for one second and it seems pretty regular (each 3-5 seconds). The RPM needle (I don't know the exact term for it) doesn't move at all during this tremble. It stays where usually is 550-600.
It does the same thing on Neutral, Reverse or parking.

I came home and I cleaned the throttle body and the maf sensor. I drove it for another 10 minutes and then again the same problem.

So far I didn't get the CEL on so I can't test to see what's going on.

Does any of you have any ideas what else should I check?

Thank you

At 150k miles, and without looking at what's been done to the car (maintenance wise) it would be near impossible to tell without a CEL setting you off in one direction or another.

It could be spark plugs, ignition coils;
It could be fuel filter;
It could be fuel injectors;
Based on your statement about it doing the same in D, P, N and while brakes are on/off, I would not assume a vacuum leak nor would I have done anything to the MAF sensor.

Some DTC codes require more than one trigger to show up as "current" rather than "pending" (examples: all misfire codes, Lean/Rich condition codes, most engine performance codes for that matter).... So if you have access to a OBD-II code reader, get a quick scan to see if any codes are pending.

It could be something as strange sounding as a bad tank of gas... Keep an eye on it, wait for a CEL but hope for none... And may be it'll go back to normal soon.

Also worth checking the evap system purge control valve to see if it's opening and shutting properly. A malfunctioning one can cause idle issues

Thank you for you answer. I bought the fuel filter today and I will try to change it. I am looking for a DIY on the forum but I can't find. I have the basic idea of how to do it because I did it before on a Audi A4. But I remeber someone told me that I should do something with a valve (Schrader - if I spell it right...).

If anyone can point any DIY I would gladly appreciate.


I'll check this as well. Any DIY would help a lot. Thanks

i think this is it hope you can see it or just google it mbworld fuel filter diy

https://mbworld.org/forums/c-class-w...ic-2013-a.html

the link is in this thread

The fuel filter they gave me is this one: http://www.napaonline.com/napa/en/p/FIL3643_0183440579

Later edit:

I found the DIY for changing the fuel filter. I'm going to do this right now.

Is it possible that this model doesn't have the fuel filter attached below?
http://www.napaonline.com/napa/en/p/FIL3643_0183440579

I opened the car underneath and have not found the fuel filter.

https://mbworld.org/forums/c-class-w...8-c-300-a.html check this out read the last post maybe someone with a 2008 who has done this will chime in

There has to be a filter somewhere. Try to trace the fuel line.

I know this is an old thread but did you end up figuring out what caused your hiccups? My 2016 amg gts is having the same symptoms, where its having slight intermittent hiccups at idle in comfort mode. No CEL nor any movement in rpm needle. Comes every 3-5 seconds.