Please help me ive just bought a 2002 audi a4 20v turbo. it has a slight misfire when at idle and seems to last up to about 3000rpm when i set off but once it is rolling all seems fine motorway no probs. it has had new coils fitted and new temps sensor both common faults i here it is high milage but has full audi service history please help any suggestion is welcome as knowbody seems to have any idea what the fault could be

 

personally i would check the compression to make sure the engine is in good condition... have you checked car fax on this vehicle??? has it had all it's maintinance regularly? any sighns of a sludge issue? .... just thinking the pcv tubes could be clogged...causing ruff running..... you can pretty easily take off the engine plastic cover and get to the pcv tubes/hoses...take them apart and feel inside with your finger....

do you have access to a vag-com? ....

 

hi mate cheersfor advise i havnt check compresion as it doesnt seem to be that majour the car drives and pulls very well just this 1 annoying thing you can feel it more when your sat in the car than you can to listen to it. it was a company car and has done a lot of motorway miles and has got full audi dealer history all the way through the book up to 3 months ago but checking the pipes sounds like a good thing to check and i will do this first thing in mornin do you suggest just clean em out check for any cracks/leaks and go from there with it.

 

Have the codes read.

 

a wire hanger can come into handy while trying to clean some of them out... other than that just use your fingers and a rag... maybe a light cleaner.. good luck!

 

Hi all today i have cleaned out all the pipes as suggested they were very sludged up, and changed the spark plugs. But it still remains the same

 

.....sorry to hear that.... now it's time to make sure your block is doing well... use a compression tester(there not very expensive if you do not have one already)... and if that check out... i'd recomend pulling the oil pan and checking the oil sump for cloggedge... it's a real pain in the a$$, but it should def. be checked if there was lots of crap in the pcv.... are you pretty mechanically inclined?? or no...

 

vacuum line!! check all vacuum lines for even the smallest hole.... if they look worn just replace them.... a small leak can give you weird drivability problems

 

Hey all sorry not not updating sooner but have a broken ankle and hant managed to get near the car however have just got it back from a garage who checked the codes for me and it was showing a boost leak and found it it had a faulty dv valve they have replaced this and given the engine a good look over and checked its condition and all is well but the problem is still there still misfires on tickover the garage said they checked over all the hoses and there is no leak but when they clear all the codes and drive the car it comes back up with a boost leak. Im thinking maybe pressure test the system myself and see what i can find any more ideas are more than welcome cheers