Hi guys, I’m so excited to find this forum - especially the C6 S6 V10 info dump!!! I’ve been searching for an accurate and detailed source of V10 knowledge for awhile now, but it’s hard to come by.
I’ve got an 2007 S6 I bought last year in DC and then, after a sudden relocation, took overseas to BG. I actually tried to sell it before I left, but couldn’t get a bite above $17K so I figured I just keep it an take the fuel economy hit. And now with the price of gas in Europe down to the same as last year in DC, I feel great about it! Here are some pics I took for the listing:
Anyways, I’ve been chasing down a P0308, misfire cyl 8, at WOT for months now. I found myself a local audi mechanic who had experience with v10s (strangely, there are a ton of v10 S8s in Sofia, more than S6s) who was willing to work with me on it. We’ve done the following:
- reseal the upper valve cover gaskets to keep oil from leaking into plugs (cleared a rough idle on cold start)
- swapped coil packs and plugs from cyl 7/8
- ran through 200ml of G17 fuel additive, plus another 1000 miles
Despite the claims to the contrary in many of the forums, I think the additive did help. But it took about 1000miles for it to do the trick. Now I get a few intermittent P0300 codes at WOT, but never a CEL. My mechanic suggested I run another 200ml of G17 plus 1000 miles, and then we’ll inspect the intake manifold for carbon deposits. But at the moment, the engine is running well.
The other bugs to the system are:
- front passenger door lock mechanism will only unlock/open from the inside. once unlocked, the door opens fine
- the car was momentarily disabled (wouldn’t start). coincidentally, this happened exactly when the passenger door opened just fine. I got out, locked and unlocked the door, and then was able to start the car just fine. My theory is that the car was immobilized - maybe because the passenger door was not properly closed before opening. HOWEVER, my mechanic said that this might be a sign that the fuel pump is on it’s last legs. Apparently, the fuel pump primes for a few seconds when the doors are unlocked. Has anyone every heard of this before? Regardless, this issue hasn’t happened again.
- my mechanic suggested that if the misfires come back, he could do intake manifold ‘tumble flap’ removal mod. I’ve read about this in sigs, but can’t find any details. any thoughts?
I’m still reading through the info dump, so I’ll pipe in again after I have finished. But just wanted to say hello.