Tre'

2004 A4 Avant 3.0 Quattro with automatic trans.

My car has been idling like it is in the video randomly for a while. When it happens, it only does it when I've been driving and put the car in park and sometimes upon start up. A couple of weeks ago, the car cut off while sitting in traffic and the abs and traction control lights came on. It would start right up but would die again as soon as I put it in drive and gave it gas. I let it sit for about 20 minutes, started it and turned the a/c on full blast and the car ran fine long enough for me to get it to the dealership. The dealership said it was the mass air flow sensor, so I changed that and cleared all codes, only to find the issue still there. I get the codes for maf input too low and torque convertor stuck off. Any ideas?

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The car died again yesterday so I took another video. The only difference this time is the car jumps into gear harder than usual. I let it sit for about 20 minutes again, started it and turned the a/c on full blast and was able to drive it home, just like the last time. In this video, the last big jump in idle before the car kills was me bumping the accelerator. Would bad injectors, fuel pump or filter be the cause? If so, how did the dealership miss it?

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04_ultrasport

After you cleared the codes did you do the throttle body adaption?

a44me2

I had a similar problem awhile back, have your alternator checked. The voltage regulator may be faulty and things will get worse as voltage to various components gets out of wack. The fact that you can drive with the A/C full blast is what caught my attention. These cars will eventually go into limp mode when voltage is incorrect.

jlew39

I had that same problem once. I had the engine coolant temp sensor replaced and I had no more jumpy idle after that. I don't know if that was the cause, but thought I'd mention it considering the causality. It's a $10 sensor and fairly easy to replace. I know ECS tuning sells them, might be worth a shot.

Tre'

You might be onto something. While driving tonight, I kept hearing a tick through my speakers every few seconds, sounded like I was listening to an old record. When I got home and parked, I turned the dome lights on and they were flickering a little in sequence with the ticking sound.

Forgot to mention that my speedometer stops working when the abs and traction control light come on. I'm starting to think I might have gremlins.

Tre'

Okay, I scanned the car after it died the last time and got the following codes.

P0102 MAF Low Input
P0507 Idle Air Control System RPM Higher Than Expected
P0501 Vehicle Speed Sensor A Range/Performance
P0455 Evaporative Emission System Leak Detected (Gross Leak/No Flow)
P0741 Torque Converter Clutch Solenoid Ciruit Performance or Stuck Off

I don't want to just start replacing random parts until I find the right one.

a44me2

sounds like a large vaccuum leak. Have a look at the evap. purge valve. It is located near the passenger side firewall under the engine cover on that side. It has 2 large vaccuum lines and an electrical connection going to it. Make sure the vaccuum lines are intact and that the valve is in one piece and not cracked.