acarney

Is the attached pic what you're talking about? (Pass side; sorry about the pic, just pulled it from the video I uploaded below... Part numbers would be awesome since I won't be able to get home to look at it if I ask family to run to the dealer)

johnkk

Just google audi bypass or diverter valve. But here's the number 06A145710N. The improved valve is the one that originally went on the TT. No difference between sides. I would still test before throwing parts at it, but it's your call.

acarney

I usually don't throw parts at it, but, you guys usually are also spot on! However, I'm doing 10 to 20 hours of overtime a week and my Audi dealer is a pain to get to after work because of traffic so it was easier to ask a family member that was on that side of town anyway.

Now for the bad news, the dealer swore that part number 06A145710P was an updated version of the N part. It looks like this part fit the V8s and the VW's and ECS reports it won't fit my car... Think the dealer screwed me over again? (Not the first time they gave me a different part and promised a million times it would fit, even though you guys gave me a different #) Or do you think this will work? Going to mess with it tomorrow...

acarney

Replaced pass side DV valve and I'm still getting horrible rough idle and misfires on 3 and 4 at idle. If I slowly carefully rev it to about 2000 rpm it's smooth as butter again. I'm still thinking vacuum leak because of that; if it was bad coils wouldn't it misfire at all revs?

I have a replacement throttle body boot and gasket that I might try replacing this weekend as well... But, I don't have to put the front in service mode to replace, do I?

I might get a driver side DV as well so both will be new... But I don't know if that's the issue or not. Still can't find anything with propane... (Front or rear area of the engine...)

If its consistently cylinder 3 and 4, does that help point to any single specific vac hose/valve that might cause that? Because it's always been those two. (#1 originally misfires but since clearing codes and testing a couple times 3 & 4 have returned every time [at least four times of clearing] and #1 hasn't returned...)

johnkk

Did the old diverter valve hold vacuum? If it does and is good, you are throwing parts at the car. Diagnose before you buy the parts.
With the new diverter valve, do you still get the hissing sound when you wiggle the hose? Try clamping off both valves by squeezing the hoses with vice grips and see if the idle smooths out.

Have you pulled the #3 and 4 plugs? #3 is pass side rear and #4 is driver side front. I'd check them and people have even posted about loose plugs. Lots of valve cover leak posts with spark plug access area full of oil.

Have you swapped coils to see if the miss moves?

pr0xZen

I recently went over mine with propane, and a go with butane, not a wiff of change in idle. But a smoke test revealed the spider hose to be leaking siginificantly in 4 places.

Your seals should be well capable of holding whatever pressure your body can generate. Get a cigarette or cigar. Plug the intake at the airfilter box, before the MAF(!), pull a vac-hose. Take a big drag of the cigare/cigarette, don't inhale (dilutes the smoke). Blow it all in the hose, plug it with a finger and look where the smoke comes out. Might take several go'es to fill up with smoke.

Do the simple checks first, before swapping parts.