Symptom Chart: Notes

WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM

Condition	Possible Sources	Action
Rattle, squeaks or buzz type noise - from the bottom of vehicle	Loose or damaged heat shield.	GO to EXHAUST HEAT SHIELDS Component Test in this article.
	Loose or damaged exhaust isolators.	CHECK exhaust isolators are correctly installed. INSPECT the exhaust isolators for wear or damage. INSTALL new isolators as necessary.
	Damaged exhaust isolator hanger bracket.	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.
	Loose or damaged catalytic converter or muffler.	MOVE the exhaust system to simulate the bouncing action of the vehicle, 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.
	Exhaust grounded to chassis.	INSPECT for signs of exhaust components-to-body contact. If necessary, CARRY OUT the Exhaust System Alignment in this article.
Drone or clunk type noise - from bottom of vehicle	Loose or damaged exhaust isolators.	INSPECT exhaust isolators for wear or damage. INSTALL new isolators as necessary.
Drone or clunk type noise - from bottom of vehicle	Exhaust grounded to chassis.	INSPECT for signs of exhaust components-to-body contact. If necessary, CARRY OUT the Exhaust System Alignment in this article.
Whistles, boom, hum or ticking type noise - noise tends to change as engine warms. Noises are often accompanied by exhaust fumes	Punctures in the muffler. Broken, loose or missing exhaust manifold fasteners or gaskets. Loose heated oxygen or catalyst monitor sensor.	REPAIR as necessary.
	Exhaust system leak.	INSPECT the entire exhaust system for leaks. CHECK for punctures, 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.
	Catalytic converter.	MOVE the exhaust system to simulate the bouncing action of the vehicle, 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.
	Exhaust muffler/resonator drain hole enlarged due to corrosion.	NOTE: Check with vehicle on the ground, not on a hoist. CONFIRM drain holes are noise source. INSTALL new components as necessary.
Hissing or rushing noise - high frequency sound. Vehicle performance is unaffected	Exhaust system. Exhaust flow through pipes.	CHECK the exhaust system for leaks. 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.
Pinging noise - occurs when exhaust system is hot, engine turned off	Catalytic converter/exhaust system.	Cool down pinging is the exhaust system expanding and contracting during heating and cooling. Condition is normal.
Vibration - occurs at idle and at low speeds. Also accompanied by clunk or buzz type noise	Loose or damage exhaust isolator.	INSPECT the exhaust isolators for wear or damage. INSTALL new isolators as necessary.
	Loose or damaged exhaust isolator hanger brackets.	INSPECT the exhaust isolator hanger brackets for wear or damage. INSTALL or REPAIR as necessary.
	Damper broken or out of position if equipped.	CHECK for the correct damper orientation in this article. RELOCATE to correct position and tighten nuts to specification. INSPECT for missing or damaged damper. INSTALL new components as necessary.
	Exhaust system grounded to chassis.	CARRY OUT the Exhaust System Alignment in this article.
Vehicle has low or no power - vehicle performance complaint	Exhaust pipe pinched or crushed. Damaged catalytic converter. Loose obstruction in exhaust.	GO to PINPOINT TEST A . to test for restricted exhaust.
Vehicle has low or no power - vehicle performance complaint	Restricted exhaust (possible frozen condensate in muffler).	CHECK drain holes for debris. PARK the vehicle inside to thaw. TEST vehicle for normal operation. If concern is still present, GO to PINPOINT TEST A .
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 debris or missing heat shields. REPAIR or INSTALL new components as necessary.
Odor - described as a sulfur or rotten egg smell.	Catalytic converter.	At times, a slight sulfur smell is normal for catalytic converters. The cause is the sulfur content in the gasoline being used. ADVISE customer, no repair required.
Odor - described as a sulfur or rotten egg smell.	Rich fuel conditions. Miss-fire conditions. Excessive sulfur content in fuel.	See INTRODUCTION - GASOLINE article .
Visible rust on surface of exhaust pipes	Catalytic converter/exhaust system.	Surface rust is a characteristic of materials used on exhaust system. Exposure to heat or road salt may result in surface rust. INSPECT for perforations. If there are no perforations, condition is normal.