Exhaust System Symptom Chart: Notes

SYMPTOM TROUBLESHOOTING CHART - EXHAUST SYSTEM

Symptom Troubleshooting Chart - Exhaust System
Problem	Possible Cause	Action
Rattle, squeaks or buzz type noise - from the bottom of vehicle	Loose or damaged heat shield. Loose or damaged exhaust isolators. Damaged exhaust isolator hanger bracket. Loose or damaged catalytic converter. Exhaust grounded to chassis.	CHECK for loose or damaged heat shield. CHECK exhaust isolators are correctly installed. INSPECT the exhaust isolators for wear or damage. INSTALL new isolators as necessary. INSPECT the exhaust system components for damage or broken hangers. INSTALL new components as necessary. CHECK for loose or damaged exhaust hanger brackets or fasteners. TIGHTEN bolts to specification or INSTALL new components as necessary. INSPECT the exhaust system for loose or broken clamps and brackets. CHECK for loose or damaged heat shields. MOVE the exhaust system to simulate the bouncing action of the vehicle while checking for exhaust-to-body contact while moving the exhaust system. Using a rubber mallet, TAP on the exhaust components to duplicate the noise concern. Lightly tap on the muffler, then the catalytic converter. Determine if there are loose or broken baffles in the muffler or a loose or broken element in the catalytic converter. REPAIR or INSTALL new components as necessary. INSPECT the exhaust system for loose components. INSPECT for signs of exhaust components-to-body contact.
Drone or clunk type noise - from bottom of vehicle	Exhaust grounded to chassis.	INSPECT the exhaust system for loose components. INSPECT for signs of exhaust components-to-body contact.
Whistles, boom, hum ticking type noise - noise tends to change as engine warms. Noises are often accompanied by exhaust fumes	Punctures in the muffler.	REPAIR as necessary.
	Broken, loose or missing exhaust manifold fasteners or gaskets. Loose heated oxygen or catalyst monitor sensor. Exhaust system leak. Exhaust impingement. Catalytic converter.	INSPECT the entire exhaust system for leaks. CHECK for burnout holes, loose or damaged clamps/fasteners, or broken welds. EXAMINE the chassis for grayish-white or black exhaust soot, which would indicate exhaust leakage at that point. To magnify a small leak, have an assistant hold a rag over the tailpipe outlet, while listening for a leak. REPAIR or INSTALL new components as necessary. CHECK TSBs.
	Exhaust muffler/resonator drain hole.	CONFIRM drain holes are noise source. ACCEPTABLE condition.
Pinging noise - occurs when exhaust system is hot, engine turned off	Catalytic converter/exhaust system.	Cool down pinging is the exhaust system contracting after it has been heated. ACCEPTABLE condition.
Vibration - occurs at idle and at low speeds	Loose or damaged exhaust isolator. Loose or damaged exhaust isolator hanger brackets. Damper broken or out of position. Exhaust system grounded to chassis.	INSPECT the exhaust isolators at wear or damage. INSTALL new isolators as necessary. INSPECT the exhaust isolator hanger brackets for wear or damage. INSTALL or REPAIR as necessary. CHECK for the correct damper orientation in this section. RELOCATE to correct position and tighten nuts to specification. INSPECT for missing or damaged damper. INSTALL new components as necessary.
Vehicle has low or no power - vehicle performance complaint	Exhaust pipe pinched or crushed. Damaged catalytic converter. Loose foreign material in exhaust.	See PINPOINT TEST 1: RESTRICTED EXHAUST SYSTEM TEST .
Burning smell - usually occurs at idle, with possible traces of smoke	Foreign material caught in exhaust system. Missing heat shields.	INSPECT the exhaust system for foreign material or missing heat shields. REPAIR or INSTALL new components as necessary.
Odor-described as a sulfur or rotten egg smell.	EVAP system. Fuel delivery system. Catalytic converter.	INSPECT the EVAP system. REPAIR as necessary. CHECK the fuel delivery system. See ELECTRONIC ENGINE CONTROL (EEC) SYSTEM . ACCEPTABLE condition. A slight sulfur smell is normal for catalytic converters with less than 8,000 km (5,000 miles) and up to 16,000 km (10,000 miles). Whether for a new vehicle or a newly installed converter. Odor is due to the highly active state of a new converter.