HELP - Running on 7 cylinders

[James Todd]

Hello,

I have a 2003 S4, which is currently running on 7 cylinders.

It still pulls smooth but is massively down on power, just changed coils and still the same, anyone had any experience with this?  There are no fault codes which is confusing.

edit - I plan on changing plugs aswell but just seeing if anyone has had this. I would have thought a plug would bring up a code

cheers 

jamie

[Dan3222]

If you have no fault codes it is worth changing coils and spark plugs as these can fail easily and remarkable not give code logs.

i don't know a lot about your engine though but can guess you will have injectors, 8 of. This could well be the culprit. 

Have you identified which cylinder is not firing?

[James Todd]

Yeah done the coils today with no luck, doing plugs tmoro. Not sure if there's a way to identify what cylinder it is with no codes! 

[Dan3222]

Old school way is disconnect one spark plug at a time. When you have the offending cylinder disconnected the engine will sound no different but if you have one disconnected that is still ok the engine will sound terrible. Safest way to do it is disconnect one and start the car. Then switch off reconnect spark plug and move onto next.

change the spark plugs and see how you go. Failing that I do think it's going to be a garage job. Unless someone else can suggest something. Sorry I can't be more help than that.