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For 1990-2009 cars only

Engine Knock or Lifter Noise (Replace O-Ring)

Subject:Engine Knock or Lifter Noise (Replace O-Ring)

Models: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)



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

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