Purge Solenoid - Excessive Ticking Noise
File In Section: 6E - Engine Fuel & EmissionBulletin No.: 87-63-02
Date: March, 1998
Subject:
Excessive Ticking Noise in Ambient Temperature
(Diagnose, Replace EVAP Purge Solenoid Valve)
Models:
1997-98 Chevrolet and GMC C/K, M/L, S/T, P, G Models
1997-98 Oldsmobile Bravada
with 4.3L, 5.0L, 5.7L, 7.4L Engine (VINs W, X, M, R, J - RPOs L35, LF6, L3O, L31, L29)
Condition
Some owners may comment on an excessive "ticking" noise under certain ambient temperatures and driving conditions. Owner may describe a sound similar to spark detonation.
No DTC's are set, no driveability symptoms, or emission concerns are related to this noise issue.
Cause
The "tick" noise may be generated by the action of the plunger hitting the port seat. The stop cushion generates the noise, which may be more noticeable under low temperatures.
Correction
An improved [1][2]EVAP (Emission Canister) Purge Solenoid Valve, P/N 1997277, has been released for the above condition. The new valve appears identical to the unit it replaced. See Figure 1 - EVAP Purge Solenoid Valve, for location and P/N identification.
When diagnosing a suspected EVAP Purge Solenoid Valve for noise:
1. Check for any stored DTC's.
2. Disconnect the electrical connector (1) to the EVAP Purge Solenoid Valve and drive the vehicle.
Important:
This may set a DTC PO44O ([1][2]EVAP Emission Control System Malf.) if this test is conducted during a cold engine start up.
3. If the noise is gone, the EVAP Purge Solenoid Valve (5) is the source of the noise and should be replaced, as per the Service Manual procedure. If the noise is still present, continue to diagnose the concern using standard diagnostic procedures.
4. Clear DTC PO440, if set during the above procedure.
Parts Information
Part Number Description
1997277 [1][2]EVAP Emission Canister Purge
Solenoid Valve
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use the table.
Future Labor Time Guides will be updated with this Labor Code.