C 55 AMG overfueling, black smoke when reving.



Cant find a thread with this issue for a c 55. I went on a long trip and when I got back my rear bumper was black around the exhausts. Seems that the car is overfueling/burning too rich. What could the problem be? Could it be a dirty MAF or some kind of sensor fault? Its a '06 C 55 AMG with 140k km's on the clock.
It could be a faulty fuel pump as well, and it's delivering too much fuel to the cylinders. Or the fuel injectors are crapping out. It could be a lot of things. I doubt it, but is your engine throwing a code? If not, get your cars' ECU read anyway via STAR.

Read codes with an OBDII scanner & post.




Likely causes.
Temp sensor
MAF
Upstream O2 sensors.
Running with no Cats is illegal ~ At least fit primary Cats.
Last edited by Glyn M Ruck; Aug 11, 2013 at 11:24 AM.




Does the car really use 2 litres of oil every 200Km?? If so there is something seriously wrong & yes you will have a black bumper.
If they say the engine is OK I presume they have done a leakdown test & compression test to prove that valve guides & rings are OK. If so then a breather or similar is blocked & building up crankcase pressure & forcing blowby.
Make them give you a Star printout & post what codes are displayed. You have paid for it & you own the data not them. Don't take any BS.
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Come to think of it, it used 2lt when I rode 200km the first time I got it and as I added Mobil 1 0w40 every time it started using less. About 2 weeks ago I went to cape town for a course and filled 2lt there and 1lt on the way back and the trip was about 1400km altogether. Well the proper oil is in now so I am just going to monitor it now. So that's done but now I have a new list of issues with the quality check, but small things like castor, rear lower control arm and pilot bushes etc.
Thanks for all your help, will let you know if its better or not.
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Just wanted to let you know it looks like all is good after the oil change, went to PE yesterday, first checked the oil and said oil level is good then went on the trip and checked this morning and the oil level is still good, cant believe that oil type can make such a difference. They must've thrown some cheap crap oil in before they sold it. There is a hint of black around the exhaust tips but I guess that could probably be all the leftover s*&t in the exhaust that was blown out.
My car throws a puff of blue smoke when i take off hard ...
the car is using alot of oil also but there is no leaks at all.I fill 1 liter of oil for every 500km but thats driving the car hard .It doesnt come up with any faults on Star .
I have full exhaust on the car with no cats as well as a software tune . I tried replacing the software with a different tuner it worked well for a month or so but back to its old crap now.
I was using Mobil 1 0w 40 but changed now to Shell Helix ultra 5w40
PLEASE HELP




