S4iowa

it's gonna be a process of elimination starting with the cheap/easy fixes first...it could take some time.<ul><li><a href="https://forums.audiworld.com/s4b6/msgs/392467.phtml">https://forums.audiworld.com/s4b6/msgs/392467.phtml</a</li></ul>

daveak05

I'm willing to bet that the P0300 codes he's getting include the text "upper limit exceeded". And that usually means a bad coilpack.

But, we never did find out if the codes followed the coilpacks to the other cyls. I don't even know how many were switched around.

But, we do know that he has 3 cyls misfiring all on the same bank.

daveak05

I would have to view that as coincidental

RI A6

1) probably not an O2 sensor, since there are dual sensors. A mismatch between sensors would fire off an additional O2 code.

Note: since you're not getting O2 codes, this indicates that if the problem is an air/fuel mixture problem, that problem is minor (i.e. small leak ...) enough to keep from driving the O2 sensor out of range and firing an O2 code.

2) Could be injectors. If it's always the same 3 cylinders misfiring, then could be that those three injectors sucked something nasty out of the fuel.

3) Fuel rail regulator or pump. If the fuel rail pressure regulator was not operating correctly, that could cause misfires, and possibly also your low rpm deadspot problem

4)Fuel pressure sensor on bank that's misfiring.

5) Air leak in the intake manifold, or in the secondary air injection system.

daveak05

You just added another half dozen things for Evil to worry about : )

As for coilpacks possibly being bad...there's a much better method to determine that than switching them to the other cyls. You check the resistance of each coilpack off the car, see if it's out of spec.

The plugs, a little trickier, to find any small cracks on the insulator. But, those are a cheap fix by replacing those plugs at the cyls that are misfiring.

I'm now waiting for AoA to be called to the rescue. Which in itself is a shame.

RI A6

Technical Bulletin
Page 1 of 2
© 2006 Audi of America, Inc.

Condition Audi RS 4 with BNS engine code.

Reporting obligation prior to repair for all engine, engine management, transmission, chassis and tow-in concerns.
00 06 02 May 10, 2006, 2012103/1 Model(s) Year Eng. Code Trans. Code VIN Range From VIN Range To RS 4 2007 BNS All 8E_7N900001 8E_7N999999

Technical Background Hotline Channel Submission required for the New Audi RS 4- Authorization prior to repair for all engine, engine management, transmission, chassis and tow-in concerns. Production Solution Service Audi of America is requesting your cooperation in supplying us with technical information vital to the successful launch of this brand new model. Audi

daveak05

they are requesting that dealers advise them of repairs/procedures and get permission.

It's not the same as calling out an AoA tech, possibly from Germany, to help diagnose a problem. That's a dealer failure, plain and simple. They don't know the car as they should(training, available info) or they aren't going about the diagnosis correctly. All too common, unfortunately. And boy does it get mnessy for the owner waiting on all that!

RI A6

And, this puppy does have quite a few new systems on it, which makes it pretty tricky for techs that see it the 1st time.

However, you did mention AoA, and not Audi Germany. And according to the way the system works, the dealer should have gotten the latest troubleshooting tips from AoA. Apparently the approach that the dealer techs took was the best that the Borg collective could come up with.

RSIV

<center><img src="http://content.answers.com/main/content/wp/en/7/71/Lemon_battery.png"></center><p>

daveak05

Th AoA diretive serves a dual purpose. 1.) To exert some control over indiscriminate warranty repairs and potential high repair costs cutting into profit margins on the limited RS4. 2.) To provide valuable feedback to Audi about what type of problems owners are having with this new model...and what specific areas may need to be addressed.

I gree that the car is unique enough to potentially provide a problem for dealer techs. But, they need to step up to the plate and AoA should only be called in and send Audi factory techs out in isolated cases...not due to any dealer incompetence.