C 2500 Truck 2WD V8-350 5.7L (1988)
Air Injection Check Valve: All Technical Service Bulletins
Engine - Chirping Noise
GMC NUMBER:
88-T-85
GROUP:
6E - Engine Emissions
DATE:
February, 1988
CORPORATE
NUMBER:
836509
SUBJECT:
CHIRPING NOISE
MODELS:
1988 C1, 2 TRUCKS EQUIPPED WITH 5.0L (VIN CODE H) OR 5.7L (VIN CODE K)
ENGINES
Some 1988 C1, 2 trucks may have been built with incorrect Air Injection Reaction System (A.I.R.) check valves and may experience a belt chirping
noise at idle. This condition may be diagnosed by disconnecting the A.I.R. hoses at the check valves and repeating the condition at which the noise
occurred. If the noise is eliminated, the A.I.R. valves should be replaced
with check valve, P/N 22050642. This noise does not effect the emission system performance.
Labor Op:
J6090 - Valve, Air Check .2 hr Replace, Right Side J6091 - Valve, Air Check .2 hr Replace, Left Side
