Possible cause of hesitation, low idle, and stalling: TB and butterfly valve needed cleaning...
09-17-2003, 12:46 PM
#1
AudiWorld Super User
Thread Starter
Join Date: Mar 2000
Posts: 5,266
Likes: 0
Received 0 Likes
on
0 Posts
Possible cause of hesitation, low idle, and stalling: TB and butterfly valve needed cleaning...
We had tried everything else to rid the car of a hesitation off idle when not warmed up. Also had a low idle at times, stalling now and then. Spent hundreds of dollars and several service visits, with no improvement. They had cleaned the carbon out of the injectors and engine (needed it anyway), but no help. I even installed a new MAF and diverter valve myself.
Finally, I talked to the foreman or Rector Motors' service department, who suggested cleaning the throttle body and butterfly valve by hand using a good cleaner product. Said Audi didn't have a procedure for it, so they tend not to do it until it becomes a problem.
When I raised this with our regular service advisor at Anderson-Behel, he said "yeah, I used to need to do that all the time on my xxx car." I didn't say -- but was thinking -- "why didn't you think of this instead of charging us $700 for other procedures that didn't fix the problem?"
I'd have cleaned it myself... its easy... but the car had been flatbedded in the very same day for a broken belt and stuck belt pully. Warranty Direct covered that, fortunately.
Finally, I talked to the foreman or Rector Motors' service department, who suggested cleaning the throttle body and butterfly valve by hand using a good cleaner product. Said Audi didn't have a procedure for it, so they tend not to do it until it becomes a problem.
When I raised this with our regular service advisor at Anderson-Behel, he said "yeah, I used to need to do that all the time on my xxx car." I didn't say -- but was thinking -- "why didn't you think of this instead of charging us $700 for other procedures that didn't fix the problem?"
I'd have cleaned it myself... its easy... but the car had been flatbedded in the very same day for a broken belt and stuck belt pully. Warranty Direct covered that, fortunately.
09-17-2003, 12:56 PM
#2
AudiWorld Super User
Join Date: Sep 2001
Location: Central NJ
Posts: 3,019
Likes: 0
Received 0 Likes
on
0 Posts
Check this out - TSB on a rough or low idle
Do these guys even check???<ul><li><a href="http://www.20vturbo.com/tsb/mirror/audipdf/a240001.pdf">Engine, Fluctuating Idle or Idle Speed Too Low</a></li></ul>
09-17-2003, 02:49 PM
#5
Member
Join Date: May 2001
Posts: 17,322
Likes: 0
Received 0 Likes
on
0 Posts
Yes throttle body. TB is also used to describe the timing belt but when used in reference to the
idle etc .. it is throttle body 
It gets grimey from the oil vapors drawn in via the PCV system. The really small crude that comes in with the air that passes thru the air filter also contributes.
It gets grimey from the oil vapors drawn in via the PCV system. The really small crude that comes in with the air that passes thru the air filter also contributes.
09-18-2003, 08:25 AM
#7
Member
Join Date: May 2001
Posts: 17,322
Likes: 0
Received 0 Likes
on
0 Posts
Not nearly so simple. You need to get a new throttle body to intake manifold gasket from the dealer.
IIRC it was like 50 cents or less. Disconnect the SMIC to TB hose, unplug the TB sensor wire, pull the cable (on the nDBW) and remove the TB. Once you have it pulled use a good, I like CRC brand, throttle body cleaner to clean the outside and the inside thouroughly. Use a q tip or similar to clean the area around the throttle plate and the plate itself. Pay particular attention to the edges of the plate and the area of the body the plate seats against when closed to the idle position. Do NOT use a carb cleaner as many of these have chemicals that can raise hell with coatings and plastics oft found on throttle bodies.
Once you have everything spotless reassemble using the new gasket and do a TBA before starting.
Once you have everything spotless reassemble using the new gasket and do a TBA before starting.