
1991 GMC C2500 Sierra SLE 5.7L Heater Core
when the engine is fully warm there is a thumping noise coming from the heater box after a test drive. no sign of overheating. can feel the vibration in the box if you put your hand on it.
FIX posted 1/7/2004
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Message Closed w/FIX
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VIN | 1GTGC24K2M |
Engine | 5.7 L / 8 cyl / GAS |
Trans | 4-speed Automatic |
Delivery | FI |
Affected | Heater Core |
Conditions | Thumping Noise |
Message Closed w/FIX
Vehicle Data
1991 GMC C2500 Sierra SLE
VIN | 1GTGC24K2M |
Engine | 5.7 L / 8 cyl / GAS |
Trans | 4-speed Automatic |
Delivery | FI |
Affected | Heater Core |
Conditions | Thumping Noise |