rellascout

My 1998 Audi A8 started a little rough the other morning after sitting all weekend.

It rattled and idled rough for about 30 seconds and then it went away. The car ran fine with no issues until yesterday. The car died on me. Just before it died it idled rough and then check engine light started to blink and then stayed on and then the car would not move. Put it in park and the car will start but shakes and will not drive properly.

I towed it to my mechanic and it is shooting out P0300 codes. Multiple misfires on all cylinders in the passenger side bank. Almost constant misfires on P0301, 302,303,304.

I email PaulW and he suggested several things. Coil pack, Injector don't seem to be the issue because whatever it is effecting all 4 cylinders in the bank.

The one that has not been ruled out yet is the Power output stage. My mechanic will check that out later today.

Well that's my story. I trust my mechanic and believe he knows what he is doing but just looking for some guidance for him and some piece of mind for me. Thanks in advance.

Rick

KYNZ

so far we have changed plugs, switched coil packs, replaced spark control modules, cleaned fuel rails, cleaned all injectors. now we are looking into possible MAF issues or maybe wiring or connectors. My mechanic is stumped as are his peers and Audi Gurus that he knows/trained under. Any advice or suggestions would be greatly appreciated.

KYNZ

oh, i also tried a bottle of Techron Plus but still no luck.

tonypai

I had the same misfires. Its usually an electrical issue. My connectors were waterlogged. I blew out the drains and dried out the ECU and the misfires went away.

I'd be a little wary if your mechanic recommends replacing all your spark plugs and coilpacks.

rellascout

At this point my mechanic is not looking at those things. He is looking at the power output stage. It has to be something that is effecting all 4 cylinders in the bank.

I will have him look for water in the drains and the ECU.

Keep the ideas comming. Thanks

tonypai

Bentley gives 2 or 3 possiblities for that problem. One of which is to clean the connectors. Would have taken him 30 minutes.

rellascout

Please elaborate on the 2 or 3 possibilities please. Thanks in advance.

MP4.2+6.0

knock sensor (or its wiring) on one side that is seriously screwed up? You went through the obvious ones like coil packs, etc. Do make sure all your connectors and grounds are in good shape and secure, including at the ECU. You're about where it's time to try an ECU swap maybe, if you can find one or convince another owner of the same car to let you try his/hers.

MP4.2+6.0

Does your car have coils on plugs (newer style), or does it have coil packs with conventional plug wires? If the latter, I would be looking at the coil pack or its wiring assuming it'd divided by cylinder bank.

A8CT

Fuel pump relay on my 2k gave all those symptoms. Shouldn't be bank specific/ post above though