M271 engine problems

[Nadeemus]

Hi members. I've just joined the forum, so here goes.

I have a 2012 W204 C180cgi automatic with intermittent acceleration issues. There is a light misfire and/or light hesitation under moderate/heavy acceleration but nothing I would call permanent loss of power and no problems under light acceleration. But the problem is that it is intermittent between start ups.

I have done the following:
Sparkplugs changed all 4
Ignition Coils changed all 4
Camshaft position sensors Both
Cleaned Throttle Body
3 Bottles of Injector Cleaner

None of which has worked. It is still happening and is still intermittent. The check engine light comes on and off by itself, but no codes.

There is occasional rough idle but no starting problems and no stalling ever.

Mercedes could not replicate the drive issues (intermittent) and my mechanic hasn't got a clue now, save for guessing. Please help. I've never had a car do this to me before.

Thanks

PS
The car has had Timing Belt and Camshaft Gears about 6 months ago (OEM). This problem was present before then together with starting issues and startup noise which have all been fixed.

 

[amazighman]

Vaccum leak perhaps?
You ll find out if you get a smoke test done.

 

[markjay]

The other common issues on the M271 are split vacuum hose under the air filter housing, blocked crankcase breather, and failed thermostat, but I don't know if any of these is related to your issue...

 

[markjay]

...seeing that you already replaced the camshaft sprocket wheels and the camshaft position sensors.

 

[Nadeemus]

Thanks guys.

I'll speak to my mechanic about the vacuum leak. I'm also going to clean the maf sensor tomorrow to see if that helps.

 

[Nadeemus]

Hi guys

I'm new at this game. I changed the air filter today and looked around for the maf sensor housing but I couldn't spot it. I know where the throttle body is and I'm going to clean that tomorrow. I know the maf sensor should be close to the throttle body, but can anyone guide me to the exact location. I'm just thinking that maybe its built into some other part and it might be fully concealed from sight.

Thanks