2001 - 2003 Corvette: Service Bulletin: Engine Knock or Lifter Noise

Subject: Engine Knock or Lifter Noise (Replace O-Ring)
Model and Year:
2001-2002 Chevrolet Camaro
2001-2003 Chevrolet Corvette
2001-2002 Pontiac Firebird
2002-2003 Cadillac Escalade, Escalade EXT
2000-2003 Chevrolet Suburban, Tahoe
2001-2003 Chevrolet Silverado
2002-2003 Chevrolet Avalanche
2000-2003 GMC Yukon, Yukon XL
2001-2003 GMC Sierra
with 4.8L, 5.3L, 5.7L or 6.0L V8 Engine (VINs V, T, Z, G, S, N, U -- RPOs LR4, LM7, L59, LS1, LS6, LQ9, LQ4)
Source: Chevrolet Service Bulletin
Bulletin Number: 02-06-01-038 - (12/02/2002)

Condition

Some customers may comment on an engine tick noise. The distinguishing characteristic of this condition is that it likely will have been present since new, and is typically noticed within the first 161-322 km (100-200 mi). The noise may often be diagnosed as a collapsed lifter. Additionally, the noise may be present at cold start and appear to diminish and then return as the engine warms to operating temperature. This noise is different from other noises that may begin to occur at 3219-4828 km (2000-3000 mi).

Cause

The O-ring seal between the oil pump screen and the oil pump may be cut, causing aeration of the oil.

Correction

Inspect the O-ring seal and replace as necessary. Use the applicable part number listed below. Refer to the Engine Mechanical sub-section of the appropriate Service Manual.

Parts Information

Part Number	Description	Qty
12557752	Seal-O/Pmp (O-ring) (F and Y Cars)	1
12563963	Seal-O/Pmp (O-ring) (C/K Trucks)	1

Part Number

Description

Qty

12557752

Seal-O/Pmp (O-ring)

(F and Y Cars)

12563963

Seal-O/Pmp (O-ring)

(C/K Trucks)

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation	Description	Usage	Labor Time
J1060	Pickup Tube and Screen - Replace	F Car	3.7 hrs
		Y Car	4.3 hrs
		C Truck	1.3 hrs
		K Truck	2.1 hrs

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.