Misfire cylinder 3

[nchamberlain140]

Morning All,

Driving to work in my 2003 Super V8 this morning and the engine light flashed at me this morning went off, filled up with petrol then came on and stayed on accompanied with slight lumpy running. Plugged in the diagnostic tool and I am getting 'misfire on cylinder 3'. Is this a case of just checking/replacing sparkplug/coil, or could it be something more serious and/or difficult to resolve.
Also, does anyone know what one cylinder 3 is?

Kind Regards
Nick

[nchamberlain140]

Ok, so the plot thickens, so I swapped out the coil for the one on cylinder one and I get a new misfire code for cylinder 1, must be the coil right? But I also now get a misfire error for cylinder 8?? Any ideas???

[jeff1954]

If the engine isn't misfiring on No 8 I would ignore it and put a new coil on No 1 delete all the codes and se what happens just make sure you haven't disturbed anything to do with No 8 before you start the car.

[nchamberlain140]

For the sake of £13 for a col from British car parts I replaced them on cylinder 1 and 8 and changed all the spark plugs while I was about it.
Looking at the state of the plugs I took out I was surprised the car ran at all, so worn!! Running very sweet now.
Thanks for the advise.

[iRS]

Nick, well done for getting it fixed. How easy was it to change the plugs? I've been meaning to change mine on my Super V8 for a few months now. I hear some are diffecult to access?

[BrianG]

A note generally: worn plugs can cause coil failure as the internal flashover spark gap protector does not always save the coil. I learnt this the hard way when I had an X308. For the X350 change them before the 100K miles guideline on the service sheet. Always buy the correct genuine iridium plugs: they are fit and forget until the time comes to change them again.

[nchamberlain140]

Hi Roger, sorry for the delayed response, it was a bit of swine of a job, with the right hand bank especially the back two closest the bulkhead, proving the most tricky. I did not really have to remove anything, just lots of unclasping certain wiring looms and pipes and lots of bending of the plastic box where the pollen filter sits. A stubby socket set and telescopic magnet tool proved useful. I think it took me over three hours all told, and quite a bit of skin missing from my knuckles!
Good luck.

[nchamberlain140]

Thanks Brian, I have put quite a few hundred miles on it since changing and have not had any problems thus far so hopefully only those two coils were damaged. Seeing as they were so cheap I did buy a couple of spares which now sit in the boot just in case.