Number: 86-234

Section: 6C

Date: APRIL 1987

Subject: FUEL RETURN PIPE RATTLE/KNOCK

Model and Year: 1985-86 CORVETTE
TO: ALL CHEVROLET DEALERS

Some 1985-86 Corvettes may exhibit a hammering/knocking type noise audible in the vehicle passenger compartment after a cold start, which normally diminishes after 3-4 minutes of engine operation.

This condition may be caused by pressure pulsations in the fuel system generated by fuel injector operation, resulting in hydraulic hammering in the chassis fuel pipes.

Vehicles exhibiting this condition may be repaired by installation of a filter-accumulator assembly in the fuel return system. Service kits containing required parts and installation instructions are noted below by body style and are available from GMSPO.

Labor Operation Number: T1195
Labor Time: 1.4 Hours
Add: 1.1 Hours for Convertible