Misfire on 4,5,6 reported!! Help?

[stevesey]

Journey home tonight was fine - until almost home then I tried an quick pull away at a roundabout and the car didn't take off.

Just plugged her in and trouble code P0304,0305,0306 are being reported (Misfire on cylinders 4,5,6). Aside from the fact the car won't rev - it is driving normally when you take it easy. MAF was replaced 6 weeks ago and I did red-line it last week and all was fine then.

All sensor reading look fine and 02, fuel trim etc is pretty close across both banks.

As the car is running fine I'm a little puzzled - what's common to one bank that could be causing this.

Also which bank is 4,5,6 - driver or passenger?

 

[lynall]

Do the v6 engines suffer from the wiring loom probs the straight sixs do?



Lynall

 

[stevesey]

No (well never seen it mentioned).

 

[stevesey]

Been out this evening, car was fine when I floored it on the way back - will read the codes again tomorrow (in fact may try logging a section of journey on the OBD data logging stuff I've been working on).

Didn't say earlier but the car was low on fuel when it started playing up earlier - only got 60 litres in though (my record is 62 and it's supposed to be a 67 litre tank isn't it) wondering if I managed to get some air in the fuel line and ended up with with air on the fuel rail on one side of the engine.

 

[123ianmartin]

Did you get the problem sorted? i have the same problem with my v6?

 

[stevesey]

Went away - put it down to low fuel Have done 2K miles since, but now being a bit more careful not to push the fuel guage so far into the red.

 

[ron123wdf]

Hi I had the same problem a few weeks ago it turned out to be a plug lead on no 5 cylinder breaking down under the plastic cover between the coil and plug cap.
I also changed plugs which had only done half life Mercedes recon but were completely worn out mine showed low volts on lh O2 sensor when missing as both our cars are same age its worth checking, 12&3 are on rh side 45&6 lh side.
Regards Ron