Mark6555

Recently the oil cooler seal broke on my A6 and leaked huge amounts of oil. It was the middle of winter (about -20 F outside), so I did what I thought was best - I used my spare 0W-40 bottle and filled the oil back up and kept driving to the mechanic. In my haste, I spilled some oil down the side of the engine. After the mechanic replaced the seal, I found the engine was having misfires. The mechanic thought it was likely from the oil I had spilled down the side.

However, my code reader says that I'm getting misfires on the opposite side (1, 2 and 3 - the oil cap is on the 4, 5, 6 side). I noticed that there is, indeed, quite a bit of oil on the 4, 5, 6 side, but none on the 1, 2, 3 side. I also noticed that the breather tube (I think it's called?) to the 1, 2, 3 crank case had been severed a long time ago and duct-taped back together. The oil had got into this and had caused the tape to come undone.

I wiped the codes on my OBD-II scanner (since I had so many old ones which were fixed) and now the 1, 2 and 3 misfire doesn't seem to show up, even after idling for a long time and driving it around the block. The engine still runs very rough and power is severely reduced (very slow acceleration). The only codes I get now are P0150, P1519 and P0102 - nothing about misfires.

I've done some repairs on the car myself before, but I'm no expert. The mechanic couldn't get his reader to work (I later found out because of the aftermarket radio) and wanted to charge around $700 to replace all the spark plugs and coils, without being sure that this would fix it. He sounded like he didn't want to deal with it anymore. I'd like to try to repair it myself, but I'm not sure where to start.

Does anyone here have any thoughts on this? What might be going on, further things to test, possible fixes? I'd really appreciate any help I can get. Thanks!


Here's a photo under the hood (you can see the new duct-tape I added in the top right - replacing the old duct-tape temporarily to see if it fixed anything, which it didn't seem to). I couldn't work out how to size photos on here, so I've just put it in a spoiler. Let me know if I should upload more photos to help diagnose it.

georgeb944

Of course, we assume that you have checked for spark on each of the cylinders...

You should also check that the injectors are getting a good pulse, using a noid light.

That said, I think that the P1519 might be the problem, based on the bank 1 misfires.

The Ross Tech wiki for that MIL is a clue...
17927/P1519/005401 - Ross-Tech Wiki

Harleyguy

+1 on georgeb's response. DO NOT pay the mechanic that much. The cost of the parts to do that is about half or less what he quoted you and may not be the solution, hence you are out $700 and the problem remains.

Mark6555

Thanks very much for the replies and sorry for the late response. I haven't checked for a spark in each cylinder and I'm not sure how to on this model (I haven't done any work on engines before - just CV axles, brakes, simple stuff).
However, I did remove the spark plug wires from the valve cover and found that there was oil on the ends of them for cylinders 1, 2 and 3. In fact, 2 was dripping in oil and when I looked down at the spark plug, it was clearly drenched. I check the other side (4, 5, 6) and there was some oil higher up on the wires, but none at the end where it connects to the plugs, and none on the plugs. I'm not sure how the oil got into 1, 2 and 3, since the wires only had oil at the ends (so it doesn't seem like the oil got through the top at least).

I'm considering taking the valve cover off and replacing the spark tube gaskets (I think they're called?) and valve cover gasket and cleaning up the oil while I'm there. Does this seem like a good idea? I'm worried that maybe there is a deeper issue which would be causing this, but I don't have experience with engine issues, so I'm not sure.

Thanks again for your help! You guys are life (or at least wallet) savers!