I own an 2006 A4/B7 2.0T S-Line (will post pictures soon). Within the last few weeks I have had trouble with the engine idle. When stopped the engine idle becomes pretty rough--a noticeable shudder at varying tempo--occasionally slams into gear when starting from the stopped position. Never had this problem before.

I took onepoint8tee's advice and stopped by autozone to have my check engine light read. The following codes came up:

P0507: Idle Control Sys (RPM above expected)
P0171: Sys to Lean Bank 1
P0642: Sensor A Reference (Voltage CKT Low)
P2004: Intake Manifold (Runner Stuck Open)
P0171: System to Lean Bank

Any tech-savy folks out there offer advice/familiar with these codes? Thanks!

 

You need to go to the dealer have have two things adapted.
1. The intake manifold flap motor
2. The throttle body

After the dealer does this they will erase the fault codes, if any of the fault codes come back then we can figure out whats faulty.

 

Thanks man--appreciate it! Have an appointment to get it looked at on Tuesday--will post findings/outcomes after.

 

If your'e under warranty let the dealer fix it.
Otherwise, check for vacuum leaks and do a throttle
alignment.

 

Well, the car is still in the shop.

The dealership had to order a new valve--after it was fixed the car rode fine on the highway. However, the next day I drove around in 'stop-n-go' traffic and the tach would take a hard spike then dip and return to normal rpm's. The engine died once during this process--wasn't really happy about it. It only seems to spike/dip when I brake hard or come to a complete stop. So, I called the dealer and set up another appointment and brought it back to the dealership. The dealer/tech's thought it might be a quick fix throttle plate issue--but it was clean and everything checked OK. Even took the tech for a ride to demonstrate the issue--he thought it might be a transmission issue-- however, they called today and said it wasn't the transmission--no fault codes are registering with it either--and they want to keep it and run further tests/diagnostics.

I'm at a loss--anyone have this happen before? Any suggestions?

Luckily, I have another 5K before my warranty runs out. Haha!

 

just got my car back tonight. 4 days in the shop and still throttle dips. initially throttle dip was about 200 rpms; and was tight-- but still noticeable. after driving home, about 100 mi trip, the throttle dip was back down to 600 rpms and noticeable when coming to a stop.

haven't called to reschedule an appt with the dealership again but will.

the invoice first trip states:
"fnd check engine light on gff reveals faulty crankcase breather. nec to plreace breather to repair. 06f-103-483-E gasket, 06f-129-101-f valve." also had 45000 schd service, filterelem and 21 pt inspection"

second trip invoice states:
"fnd engine shudders when coming to a stop. contacted tech line and was advised to readapt trans and clean throttle place. checks good after. transmission fluid check."

================================================== =====

any tech recommendations or advice? thanks again for any help--it's really appreciated!

 

He performed a TSB to change out the PCV valve which i don't think is the problem.

Do you have a CVT transmission? (front wheel drive) That could be why tech line was asking to re-adapt it.
If you do have the CVT transmission thats the source of the studdering but audi can't do anything about it until it either throws a specific fault code, or you raise hell and call AOA (audi of america) and demand a repair and threaten the lemon law.
Its gonna get worse if you have a CVT, most of the time it requires replacing the tranny.

Now if you have quattro then im at a loss as to why your engine would dip in rpm's, it doesn't make any sense. Anything the engine would have wrong with it would throw a fault code for it, so i highly doubt it has anything to do with the engine.

 

Yeah, it's FWD and not a Quattro. I'll modify my signature to include that. The engine itself is running pretty tightly--especially after the 45K service. However, it still sporadically (probably 2/4 stops) throttle dips (anwhere from 200-600 rpms)--just not as pronounced as before--it does the same when shifting gears (i.e. Park to Drive, Drive to Reverse etc).

The tech's at the dealership were stumped with the problem when I took it in before. I called and set up an appt for Tuesday.

I'm worried about it being isolated to a transmission problem and the dealer waiting until the warranty runs out and the onus is on me to foot the bill. I'd rather them isolate/identify the problem now and replace parts neccessary (i.e. transmission) now before I have to get it towed up there--but I guess that goes without saying really.

How much is a new transmission? Are lemon laws restricted by state? Never had to worry about that before- I bought the car in WA-- live in OK now.

Thanks for the help man, really appreciate it.

 

Lemon laws vary from state to state, but most of them include if you take a vehicle in 3 times and the problem is not resolved you have grounds for a new vehicle under the lemon law, you would have to contact an attorney to find out for sure.
A new transmission would cost you $5,000 plus the labor to change it out, you don't want to do that. Let them try to fix it again, and if they can't contact your lawyer.