a4 2.5 tdi misfire
Hi ive just done a 500 mile round trip in my 01, a4 2.5 tdi quattro i noticed halfway through the journey it was down on power on the motorway, but once i came off at a slip road and stopped the engine is vibrating and feels like it only running on 5 cylinders you can feel it through the floor and steering wheel, theres no engine smoke atall, no odd noise's its just running roughly, Ive only had the car 2 days, and i was really starting to love it!. Has anyone got any ideas or tips that i can try out to solve the problem?? any help would be much appreciated
It sounds like it could possible be an EGR valve problem. I wouldn't use it and would take it to a garage and get it scanned for fault codes with Vag.com asap.
Be warned, when mine did this about three miles later it died as the idler pulley on the timing belt was disintegrating and the belt had skipped.
thanks for the reply
Originally Posted by quattrojames
The car has full audi service history with the same dealer in doncaster its last service was 4k miles ago and the belts were changed at 75k miles, so i would be very supprised if it was the idler pulleys?? aren't they changed as part of a cambelt service at audi?.
Ive just been outside and started her up its running fine on all 6 cylinders but im still oddly geting this vibration through the car the engine moves more than it did do, it's not rocking side to side much but it is moving like something is unbalanced. the problem is worse at 1500rpm then it evens out and all is smooth above this. how can i rule out the egr valve?, does this car have a dual mass flywheel??.... this is where im starting to worry
Last edited by Leea4tdi; 12th April 2009 at 13:31.
I thought that yeah
Originally Posted by Leea4tdi
If the belts were changed at 75k thats fine, whats the mileage now?
Seriously they should be yes, check your invoice to confirm. After I bought my replacement engine 6 days later the bolt holding the tensioner pulley on broke - so bad things can happen unfortunately!
If it is firing on all six again now then I can't see it being a timing problem in all honesty. You really need to get the codes scanned which will 99,9% give you the answer rather than us speculating here. Sounds like a low speed running problem, could be any one of a number of sensors or anything.
They do have DM flywheels but I think that would manifest itself through clutch slip first rather than a vibration.
You could try disconnecting the MAF - if it runs better then it will be that, it it makes no difference then it won't be. Is it down on power? Sounds unlikely to be a MAF problem from what you have said.
I'll get in contact with audi in doncaster and see if they can give me the full rundown of what was done to this car when it had the belts changed, Just taken the car for a spin to check on the power and no it still picks up and accelerates really well and quite smoothly although i can still feel the vibration as the engine revs build up but it is much more noticable at idle.
I'll be getting the car into a garage as soon as i can, and i'll keep you all posted. car is now on 105k
All fixed now, it was the dual mass flywheel