gpinard

Last Sunday I started the car to pull it out of the driveway and it was running very rough. I took it around the block and it sputtered and cough with very little power. The Check Engine Light and the ECP lights were both on. Called the dealership who said to bring it in - no power and ran rough all the way there.

Initial diagnosis was a misfire in #8 cylinder. They swapped coils and same problem. Because it is under warranty dealer connected with Audi who asked for a compression test. Took 5.5 hours because of what had to be removed. Compression test checked out. Mechanic bore-scoped the cylinders and #8 had a pool of oil on top of the piston and a line of burnt oil on the side of the cylinder bore indicating a leak from the top that ran down the cylinder wall.

Audi has asked for the head to be pulled to inspect - head gasket, valve seals, cracked head/block ??? Apparently the head cant be removed with the engine in so they have to pull the engine and tranny to do this exploratory surgery.

Has anyone seen or heard of a similar issue? My dealer says this is the first problem they have experienced with the 4.0 engine.

gk1

Sorry. That is some major surgery. How many miles? Did you have blue smoke coming out of the tailpipe when you drove it?

gpinard

56,000 kilometres (35,000 miles) - never noticed any blue smoke. I had to add 1 litre of oil between services but was told that was normal for Audi by the dealer.

gk1

Hmmm. That's odd. With a pool of oil on top of the piston I'd think that would certainly be seen as blue smoke when running. Unless the oil came from the valve cover gasket around the spark plug when they took it out to inspect?

gpinard

It is odd - certainly I would have expected a cloud when I first started it but with being a relatively new car I wouldn't have expected this so never really looked for it.

The oil is definitely not disassembly related - on the bore-scope you can see a streak of burnt oil on the side of the cylinder wall. It looks like when I parked it hot, the oil leaked down from the head area along the cylinder wall where is was burned (leaving a residue) and then pooled on top of the piston.

My guess is valve stem seal - maybe more of a wish than a guess because that is simple to fix as opposed to a cracked head/block or a leaking head gasket.

Will know more mid next week and will let everyone know.

redrocker55

Subscribed...hope this is a quick fix for you.

schalliol

You're within 15k of warrant expiration. I'd ask AoA to give a bit of extra warranty. This is like pulling someone's brain out of their head, doing some tweaking and putting it back in. Issues could crop up not immediately.

gpinard

2 weeks later and I picked up the car today . . .

What did they find - nothing!

Audi's technical rep decided that before they started taking the engine apart they should remove the oil in cylinder 8 and see what happens. They did and it ran perfectly.

Service manager took the car home two nights in a row to see if they could recreate the problem - car ran perfectly. They scoped the cylinder again and there was no oil.

They have a theory that it could have been a sticky scraper ring or a leaking valve stem seal that freed itself up through the testing process. A bit hard to imagine but dont know what else to ask them to do.

I am going to drive it for a couple of weeks and then take it back to have the cylinder scoped again.

The car is still under warranty - i purchased the upgrade to 100,000 km or 5 years so I have some time to watch this.

Will let you know if the problem comes back . . .

gk1

That certainly is strange. Does the car sit for long stretches?

gpinard

Not usually but i recently had a minor medical issue that resulted in a suspended license for 3 months - the car sat for most of that period.