Contents Wiring diagrams Section: Exhaust All sections

Engine Exhaust System: NVH GMC Envoy II

Exhaust Noise

ConditionAction
CAUTION: While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system. DEFINITION: An audible or physical noise due to a faulty component or damaged components causing a loose or misaligned exhaust system resulting in a rattle or vibration noise (buzz, groan, hum).Refer to Symptoms - Engine Exhaust prior to beginning this table.
Popping or hissing noiseExhaust leak Refer to Exhaust Leakage
Loud exhaustCompare to a known good vehicle. Inspect for a damaged or failed muffler or resonator. Replace the faulty muffler or resonator. Refer to Muffler Replacement .
External rattle or vibration noiseInspect for a bent or loose hanger, loose heat shield, or loose clamp. Inspect for a exhaust pipe causing interference. Repair or replace the affected component. Refer to the affected component's service procedure.
Internal rattleTest the components by tapping with a rubber mallet to confirm a rattle. Replace the faulty catalytic converter, resonator, or muffler. Refer to one of the following procedures: Catalytic Converter Replacement (4.2L Engine) Catalytic Converter Replacement (5.3L Engine) Muffler Replacement
CAUTION
While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system.

Exhaust Noise