View Full Version : only when the ac and heater are on

10-11-2006, 08:50 AM
Hey guys i notice some vibrations in my car when i put the ac or the heater on. The car idles so damn smooth when these features are off and it seems like as soon as i turn one of them on, my car kinda shakes or hesitates. THis doesnt effect the performance of the car, it just ruins the idle. You can totally feel it yet, its not extreme. I just like to have a car that idles perfectly without vibrations. it feels as if i have huge cams in the car or something. hahah

does anyone else have this issue. what did you do to fix it.

10-11-2006, 11:29 AM
idle air control valve?

10-11-2006, 12:18 PM
if its not that^^, i've heard of this happening with lightweight crank pulleys and/flywheels (didn't see any in your sig though). something about throwing off the harmonics and such

10-11-2006, 12:22 PM
interesting. does anyone know how expensive or what part number that valve is. i have a 99.5 a4 1.8t squatro. AEB

10-11-2006, 12:25 PM
ehh just called the dealer. he told me they are also called cut off valve. he said they go bad all the time. 75.00

^^^^^ EEEK

Betty Humpter
10-11-2006, 12:28 PM
That sux!