Audi A3 2001 1.8T: The engine light is on but problems only occur when the car is warm. Short journeys are no problem, but after a long drive when in traffic (at a stand still) the revs jump up and down to the point where the engine keeps cutting out. The idle control valve has been replaced. What else could it be?

John Weathers

• 409 Answers
• Posted on May 13, 2009

SOURCE: A4 2.0 TDI. Rough idle

You could have a bad air flow sensor. Do you also have a lack of power??

SOURCE: 2006 Audi A4 - I have an ECU code P0299 -002 lower limit exceeded

You have to pull the code to know what's wrong, do you have any drive ability problems?how different is the car driving after the light come on?

SOURCE: Electrical problem Audi A4

ELECTRONIC STABILITY PROGRAM ( ESP) LIGHT FLASHES TO INDICATE UNSTABLE DRIVING CONDITIONS....WHICH WILL ALSO COME ON IF YOUR ENGINE IS MISFIRES.. CHECK THE COILS AND SPARK PLUGS FIRST THEN GO FOR FUEL..INJECTORS...FUEL FILTER CHOKED..HOPE I WAS OF SOME HELP TO YOU..

SOURCE: Car starts ok then cuts out

HI,HANNAH,I SUSPECT YOU HAVE AN IMMOBILIZER PROBLEM.IF THERE IS A ORANGE LIGHT FLASHING ON THE CLUSTER WITH AKEY IN IT THEN IT IS THE IMMOBILIZER.THE PROBLEM WOULD MORE LIKELY BE THE DATA FROM THE KEY IS NOT GETTING TO THE IMMOBILIZER CONTROL UNIT,USUALLY A BAD CONNECTION AT THE READER COIL ON THE IGNITION.YOU MUST CLOSE THE TERMINALS SLIGHTLY AND INSULATE THE WIRING SEPERATELY.ANDY

SOURCE: audi a4 2.8 quattro idle valve

there is no carburetor on these cars , the idle air control valve is an easy thing to change it is on the passenger side near the firewall on the back of the engine buy the new one so you know what it looks like it has a wire connector on top 2 bolts and a gasket behind it just unhook it unbolt it remove the old gasket install the new one with the new gasket and plug it in simple there is no sealer required