I have a 2004 a4 1.8t. I have been having this problem continuously for a year and a half. When my car runs and gets warm after about 45 mins of driving it begins to hesitate though every gear with rpm rising until it finally catches gear. I can never get over 65mph. After this accurse for about 15 mins the car will shut off completely. I let it sit for a bit and then turn the engine over and try to drive it. It runs rough and bucks on me and then shuts off again. (no check engine light ever comes on through out this whole ordeal) It will occasionally run for a little before it shuts off on me again never getting over 45mph and bucking through every gear. When the car is not run for a long period of time I have no troubles and it drives perfect. After all this accurs if I let the car sit and cool down it runs like nothing ever happen. I have been through 2 transmissions, cam shaft work, e.c.t sensor replaced, auxilary fan control module replaced, thermostat replaced, engine coils replaced, new spark plugs and still with no success. I'm running out of patience, ideas and money. Please help .......

 

Maybe an ECU or ground problem?

 

Heat causing an issue with the turbo, throttle body, or fuel pump?

 

I haven't had any issues with the turbo system, and nobody has mentioned anything about the other things mentioned. I will have to look into the suggested solutions. I have had it looked at by an Audi dealership on 4 different occasions and every time it's a different diagnosis. I don't know if they r jerking me around because it was under warranty or they just don't know what the problem is. I'm still not to familiar with my car yet so I feel really dumb when it comes to problem solving. It's my first Audi. The car has been a nightmare for the past year and a half. Once I get this problem fixed I can finally put some upgrades into it. Almost $10,000 worth of work and no after market parts, damn it man. Thank you for the suggestions. Every little bit helps

 

Dealer tech like to over look things.... That sounds like a lot of wasted money.

Could be a fuel pump issue, but sounds like you need a guys Indie Shop...

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