Misfire

Mazin Bayoumi

Member
Joined
Apr 2, 2019
Messages
19
Reaction score
8
Your Mercedes
C320/2008/3L diesel
Hi, i'm a bit dumbfounded!! My W204 C320 cdi sport started "misfiring" at around 2000 revs when driving in auto mode. It was OK up to 2000 and over 2500 revs. I took it to a garage, they plugged it in and it showed no fault codes. They checked the injectors and "calibrated", cleaned the egr valve, checked the turbo and everything was functioning as expected. They don't know what the problem is and of course I don't either.
The car is on approx 68500 miles and was serviced in October and has a full service history.
I'm now driving a van instead of my car!!
Please help!!
 

John Laidlaw

Senior Member
Joined
Nov 15, 2013
Messages
26,375
Reaction score
9,053
Location
Wirral
Your Mercedes
BMW 530d X Drive Tourer M Sports
Still sounds like injectors to me
 
OP
Mazin Bayoumi

Mazin Bayoumi

Member
Joined
Apr 2, 2019
Messages
19
Reaction score
8
Your Mercedes
C320/2008/3L diesel
  • Thread Starter
  • Thread starter
  • #3
How is that proved without taking them out and bench testing? And if it is an injector, can it be repaired or is replacing with new the way forward? I'd have thought they'd all need to be worked on or replaced?
 

vincentfishing

Senior Member
Joined
Oct 31, 2019
Messages
216
Reaction score
172
Your Mercedes
ML270, 2003
How is that proved without taking them out and bench testing?
Do a quick simple cheap leak off test to see if one injector stands out as excessive. you can do this yourself at next to no cost.will give you a good idea of condition of your injectors.
could be that your misfire can be felt at 2000rpm but as you increase the revs in a v6 diesel(I presume) it will smooth out the misfire the faster the engine spins ,so you still have misfire but cant feel it, when I drove my 5cyl diesel with one cylinder disconnected it felt pretty smooth at 2500 revs
 
OP
Mazin Bayoumi

Mazin Bayoumi

Member
Joined
Apr 2, 2019
Messages
19
Reaction score
8
Your Mercedes
C320/2008/3L diesel
  • Thread Starter
  • Thread starter
  • #5
Yeah over 2500 revs it smooths out for while but then it feels like the turbo is shut off and we go into limp mode.
I'll get the car back on Monday and try the leak off test. Thanks
 

vincentfishing

Senior Member
Joined
Oct 31, 2019
Messages
216
Reaction score
172
Your Mercedes
ML270, 2003
off and we go into limp mode.
sounds like its going into limp mode, surprised no fault codes show up, I,m guessing the garage youre using isn't mb and not using mb diagnostic? , if not, might be worth posting your location and hoping a member might help with mb diagnostics, the reason I say this is one of my diagnostics is supposed to read mb faults but when ive tested it against my mb11 diag is was woefull compared to the mb11
 
OP
Mazin Bayoumi

Mazin Bayoumi

Member
Joined
Apr 2, 2019
Messages
19
Reaction score
8
Your Mercedes
C320/2008/3L diesel
  • Thread Starter
  • Thread starter
  • #7
I'm not sure what diagnostics they use but yeah they're not an mb specialist garage. They do have an amazing range of cars they work on though from M5s to lambos to masaratis to classics so I assume they're well equipped for all makes and models
 

vincentfishing

Senior Member
Joined
Oct 31, 2019
Messages
216
Reaction score
172
Your Mercedes
ML270, 2003
I'm not sure what diagnostics they use but yeah they're not an mb specialist garage. They do have an amazing range of cars they work on though from M5s to lambos to masaratis to classics so I assume they're well equipped for all makes and models

''They didn't know what the problem was'' doesn't inspire confidence,
 
OP
Mazin Bayoumi

Mazin Bayoumi

Member
Joined
Apr 2, 2019
Messages
19
Reaction score
8
Your Mercedes
C320/2008/3L diesel
  • Thread Starter
  • Thread starter
  • #9
This is true, and sounds like they ran every diagnostic they had at my poor car. I just don't want to have to pay for the time they spent on it... Then take it somewhere else to have to pay for the same tests and more. I suppose I'll have to bite the bullet and go to a merc specialist
 

John Laidlaw

Senior Member
Joined
Nov 15, 2013
Messages
26,375
Reaction score
9,053
Location
Wirral
Your Mercedes
BMW 530d X Drive Tourer M Sports
Give us a clue where you are and we can recommend someone hopefully
 

vincentfishing

Senior Member
Joined
Oct 31, 2019
Messages
216
Reaction score
172
Your Mercedes
ML270, 2003
Do the leak off test,you have nothing to lose, could save you a fortune, if it is an injector you can take it out get it reconditioned fairly cheaply and refit , if you put it into hands of garage it could cost you more than car is worth.
 

mattkh

Senior Member
Joined
Aug 2, 2006
Messages
2,507
Reaction score
217
Location
England
Your Mercedes
A160 W168 1999 1.6
Hi, i'm a bit dumbfounded!! My W204 C320 cdi sport started "misfiring" at around 2000 revs when driving in auto mode.
Please help!!
Does it misfire when it is NOT in auto mode?
 

js190d

Senior Member
Joined
Aug 19, 2018
Messages
641
Reaction score
304
Location
newcastle
Your Mercedes
1991 w201 190d 2.5/ 2002 s210 320cdi avantgarde
I may be completely wrong but if i was getting your issues on my 190d i would be changing the fuel filters as it sounds like an obstruction in fuel flow. Please note i don't know a lot about common rail diesels so feel free to correct or ignore.
 

vincentfishing

Senior Member
Joined
Oct 31, 2019
Messages
216
Reaction score
172
Your Mercedes
ML270, 2003
Strange even with fuel flow problem or injector problem that it starts missing at 2000revs, would have thought it would be mòre random, wouldnt hurt to change the filter if it hasnt been changed in a while, when my dad had a camper van it had random misfiring , never sure when it would happen, was dirty fuel from travelling abroad and after much head scratching filter change cured it.
 
OP
Mazin Bayoumi

Mazin Bayoumi

Member
Joined
Apr 2, 2019
Messages
19
Reaction score
8
Your Mercedes
C320/2008/3L diesel
  • Thread Starter
  • Thread starter
  • #15
Thanks for all the input. The fuel filter was changed by the garage that it's at now. The car's in Horsham, West Sussex. I'd like a garage in that area or if anyone knows someone local to there. I say misfiring arou d the 2k revs Mark but after road tests the garage told me that it was misfiring at different revs randomly but said that it's worst at low speed and revs..
 

alexanderfoti

MBO Forum Supporter
Authorised Forum Supporter
Joined
Mar 25, 2010
Messages
13,349
Reaction score
3,454
Location
Tonbridge
Your Mercedes
W221 S65 AMG - W204 C63 AMG + Various other MB's
We are not super far from you, and can help you out.
 


Specialist Classic Parts suppliers
SLS Im- & Export Handelsges.mbH, Industriestrasse 2 - 4, D-22885 Barsbuttel (bei Hamburg)
Tel. +49 (0)40 656 939-0, Fax +49 (0)40 656 939-399
Visit our website atwww.sls-hh-shop.deto view our comprehensive catalogue of parts for:
190SL (R121), 230 - 280SL (R113), 280 - 500SL/C (R/C107)
Good English spoken and friendly service to discuss your requirements.
Top Bottom