Exhaust System - Pop Noise From Underbody At Idle
BULLETIN NO.: 98-T-36ISSUE DATE: September, 1998
GROUP/SEQ. NO.: Engine-04
CORPORATION NO.: 886601
SUBJECT:
Pop Noise From Underbody After Vehicle is Parked or When Stationary at Idle (Replace Loose Exhaust Heat Shield Rivets)
MODELS AFFECTED:
1996-1998 Saturn vehicles
CONDITION:
After vehicle is parked or at idle for an extended period of time some customers may hear a pop noise from the underbody of vehicle. The noise may sound like an object hitting the bottom of vehicle and is audible inside or outside vehicle.
CAUSE:
Some exhaust heat shield to body pop rivets may not have adequate clamp load to prevent the heat shield from slipping under the head of the rivet as it expands and contracts.
CORRECTION:
The condition can be duplicated with the vehicle on a lift. Use the Tech 2 speed control special function or the PDT IAC special test to set engine speed to 1500 RPM. This will generate enough heat in the exhaust system to allow the heat shield to fully expand. With engine running, transaxle in Park, and engine speed set to 1500 RPM, raise vehicle on a lift and monitor the heat shield. As the shield is heated and expands, the loose rivet can be identified. The heat shield may have to be heated and cooled several times to pinpoint the rivet or rivets that are making noise. A fan can be used to cool the shield between cycles.
Replace the rivets that are loose. Refer to the "Catalytic Converter and Intermediate Pipe Heat Shields" or "Muffler Heat Shield" Procedure in the Isolators Section of the appropriate model year Engine/Fuel/Air Intake/Exhaust Service Manual.
PARTS REQUIREMENTS:
09442468 Rivet - Exh Heat Shield
CLAIM INFORMATION:
To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System as shown.