okay i need expert opinion i took my car to a mechanic because it had been studdering for quiet some time. 2003 audi a4 1.8t. he called me today and told me that someone had filed down the butterfly valve in the throttle body. he said in order to fix the problem he would have to replace the entire manifold and valve because they come pre calibrated from audi. is this true or is he just trying to get me for more money. if so how much does this part cost or can u purchase the butterfly valve alone. if u need more information on my car ask and ill tell i just need this problem fixed thanks.

 

Has the car done this since you purchased it? If not, I wouldn't think that your mechanic knows what he's talking about. That process would physically remove material from the butterfly valve and any negative or positive consequences would be noticed immediately. Not exactly a modification that would take time to develope a problem. Its more likely something else. Hopefully a simple fix. What exactly do you mean by studdering? Please describe what the car is or is not doing.

 

no i saw a picture of the butterfly valve and its been grinded down.

 

I guess I still don't understand then the correlation between your cars running condition and the butterfly valve. If you did not grind it down and the car has performed well for you up until recently I still would not suspect that it is the culprit. Car ran well for you before with grinded butterfly valve why is it not now? Any recent mods or anything else that has been done to the car just prior to its current disposition?