Hi guys
Auto Transmission - Idle drops about 200 RPM in D
Only in D - P,N,R just fine .

Thanks

 

my cars does something similar, lately when in drive and idle it kinda feels like its gonna die but never does, any idea as to what this could be!?

 

do you have preformance parts in your car? i fixed mine i havn't droped an rpm since last year if you have an intake its not enough air under the hood if not check your alternator the wireing harness that goes into it if the wires are corroded replace that harness and your good to go.

 

1. Unclip your air filter and very carefully check the engine air intake ducts for any hidden cracks or splits. Tape up or replace as needed.
2. With engine running, disconnect the plug to the IAC (idle air control). Does rpm change, or engine quit? If not, the IAC is the problem.
3. Is your cruise control OK ? If not, check intake system for vacuum leaks.
4. What happens to rpm. when at a fast idle (say 1000 - 1500 rpm.), you switch A/C on, then off? Rpms should jerk slightly then stabilize.