V 3500 P/U 4WD V8-454 7.4L VIN W 4-bbl (1988)
Air Injection Hose/Tube: Customer Interest
Emissions - A.I.R. Adapter Noise
GMC NUMBER:
89-6E-134
GROUP:
6E Engine Emissions
DATE:
August, 1990
CORPORATE
NUMBER:
036605
SUBJECT:
INCREASED ENGINE NOISE / NEW A.I.R. ADAPTER
MODELS:
1988-89 C3, K3 AND R2 TRUCKS W/7.4L (VIN CODE N)
CONDITION: Some 1988-89 C/K3, and R2 trucks with 7.4L engines and serpentine drive may receive customer comments of increased engine noise.
Cause:
Tube assembly between the Air Injection Reaction (A.I.R.) Management Valve and A.I.R. pump may be cracked or broken.
Correction:
A new design consisting of a bracket assembly, molded hose and adapter has been released. See the following Service Procedure:
