DeVille Concours V8-4.6L VIN Y (1995)
Idle Speed Control Actuator: Customer Interest
Throttle Body - Clicking Noise Under Dash or Hood
File In Section: 6 - Engine
Bulletin No.: 47-60-07
Date: December, 1994
Subject:
Clicking Noise Under Dash or Hood (Clean Throttle Body Bore and Blade)
Models:
1995 Cadillac Concours, Eldorado, Seville
with 4.6L Engine (VINs Y, 9 - RPOs L37, LD8)
1995 Oldsmobile Aurora with 4.0L Engine (VIN C - L47)
Condition
During a-KEY ON" or "KEY OFF," the ISC motor may ratchet. The condition may be identified as a clicking noise under dash or hood. The duration of
this ratcheting may be up to 20 seconds. The ratcheting condition may occur more frequently when starting the engine cold or at higher altitudes.
Cause
The ISC motor ratcheting is caused when the motor is commanded to extend beyond its mechanical limit. When the TP sensor learn is correct (at
minimum air, the throttle lever rests on the minimum air screw) and the ISC maximum extend position is properly adjusted, the motor will not be
commanded to move beyond the mechanical limit.
Correction
The throttle body bore and blade should be cleaned and relearned using the following procedure:
Important:
If it is suspected that the ISC maximum extend position had been adjusted without cleaning the bore, it should be checked and readjusted if required.
Cleaning the throttle bore should be performed before performing the idle speed control system checking procedure.
Throttle Body Cleaning Procedure
Remove or Disconnect
Air intake duct from throttle body.
Inspect
Throttle body bore and throttle valve plate for
deposits. It is necessary to open the throttle valve to
inspect all surfaces.
Clean
Throttle body bore and throttle valve plate using a
clean shop towel with GM Top Engine Cleaner,
P/N 1052626 or AC-Delco Carburetor Tune-Up
Conditioner, P/N X66-P, or equivalent product.
Notice: Do not use any solvent that contains Methyl
Ethyl Ketone (MEK). This solvent may damage fuel
system components.
FOR G CAR
Install or Connect
1.
Air intake duct at throttle body.
2.
Run Tech 1 TP sensor and idle learn procedure.
