The engine used to make a noticeable ticking sound once warmed up. Now it started misfiring badly. It came on pretty fast; within 100 miles it went from rare hiccups to constantly misfiring throughout the RPM range. CEL came on and now I am reading P0300, P0302, P0304, i.e. random/multiple misfires in cylinders 2 and 4.

I've the searched forums. Unfortunately most threads end with guesses but no actual solutions. I'd very much like to hear from those who actually experienced these problems and had it fixed; so that causes were more or less pinpointed.

I got 130K miles on the engine (ATW), use mobil1 synthetic every 5K-7K, and timing belt and PFR6Q sparks were done around 105K.

Thanks in advance.

 

Dunno if your year any my '05 1.8T have the exact same ignition system, but what you are describing (without the tick noise,though) is exactly what happened to me last Saturday night...I'm accelerating (hard) on a freeway ramp and..stumble, stumble,I get a flashing CEL and a NASTY miss that wont quit. I limped home, up a long hill, with what felt like NO boost [:@]and parked it 'till Momday. Talked to my service rep (at Audi) buddy, and it's turns out to be a VERY common failure mode on these 1.8T's.."ignition coils." (There's one for each plug). He said he wishes he had a dollar for every one they replaced in the last year...He could "Retire"...
Changed one out, it's back to running great.
Hope that helps..

 

The problem here is that I have two misfiring cylinders. Two coils going bad at the same time is rather unlikely. Also, my misfires came on fast but gradually. How about yours? One second everything is good and then another - a constant misfire or also at first a misfire here and there and then they became constant?

Thanks.

 

Definately sounds like ignition coils....I just had all 4 of mine replaced. Was misfiring on 1 and randomly misfiring on the other 3. If one or 2 coils are bad, you can almost bet that the others will be soon too. I'd change them all if you can.

 

+1

they're not that expensive and thats prolly what it is. btw 2 of mine went at the same, seemed like it came out of nowhere.

 

Well, that "ticking" sound your heard could be high voltage arcing in ths coil(s) that would lead from intermittent to a complete failure in the coils. My friend who is a factory Audi tech did say it is a VERY common failure mode in 1.8T's ignition systems. They're about 35 bucks each. Since mine was a warranty replacement I let them do it, but ifI keep the car (soon to be decided) I'll replace the other three that day.
I dont think two going, especially with increased load on the survivors would be a complete fantasy...

 

OK. I guess it is easy enough to test. I'll swap coils between misfiring and good cylinders and see if missfire moves.

Thanks.

 

sounds like you definitely need new coilpacks on those cylinders.