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clinebarger · 01-28-2010, 05:42 PM

This is the only TSB that comes close to what your describing. If it does have a rod or main bearing problem you shoud be able see fine copper/tin particles in the oil. Drain it into a clean container and see what you got.

Have you heard it yourself? piston slap (commen on 4.8/5.3/6.0 engines)
is a way different noise than a wiped out insert.

File In Section: 06 - Engine/Propulsion System

Bulletin No.: 01-06-01-028A

Date: March, 2003

INFORMATION

Subject:
Engine Knock on Cold Start

Models:
1999-2002 Chevrolet and GMC C/K Pickup and Utility Models
2002 Cadillac Escalade (2WD)
with 4.8L, 5.3L or 6.0L Engine (VINS V, T, Z, U - RPOs LR4, LM7, L59, LQ4)

This bulletin is being revised to add an additional engine to the models section. Please discard Corporate Bulletin Number 01-06-01-028 (Section 06-Engine).

Some of the above vehicles may exhibit an engine knock noise that begins in the first 19,000-24,000 km (12,000-15,000 mi) of use. The knock noise is most often noticed during initial start-up and typically disappears within the first 5-30 seconds (may last longer in extreme cold temperatures). The noise is usually more noticeable on the initial start-up when the temperature is below 10°C (50°F) and may be more pronounced on the first cold start following a long trip.

This noise may be caused by an interaction between carbon that has formed on the piston, the piston motion and the cylinder wall. GM Powertrain Engineering, and an analysis of engines with this condition, has confirmed that the noise is not detrimental to the performance, reliability or durability of the engine.

THIS NOISE DOES NOT HAVE ANY EFFECT ON THE LONGEVITY OF ANY OF THE ENGINE COMPONENTS.

Important: At this time, attempts to repair this condition by replacing the engine assembly or pistons are not recommended.

01-28-2010, 05:42 PM	#2
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: Engine noise 2000 Tahoe 5.3 This is the only TSB that comes close to what your describing. If it does have a rod or main bearing problem you shoud be able see fine copper/tin particles in the oil. Drain it into a clean container and see what you got. Have you heard it yourself? piston slap (commen on 4.8/5.3/6.0 engines) is a way different noise than a wiped out insert. File In Section: 06 - Engine/Propulsion System Bulletin No.: 01-06-01-028A Date: March, 2003 INFORMATION Subject: Engine Knock on Cold Start Models: 1999-2002 Chevrolet and GMC C/K Pickup and Utility Models 2002 Cadillac Escalade (2WD) with 4.8L, 5.3L or 6.0L Engine (VINS V, T, Z, U - RPOs LR4, LM7, L59, LQ4) This bulletin is being revised to add an additional engine to the models section. Please discard Corporate Bulletin Number 01-06-01-028 (Section 06-Engine). Some of the above vehicles may exhibit an engine knock noise that begins in the first 19,000-24,000 km (12,000-15,000 mi) of use. The knock noise is most often noticed during initial start-up and typically disappears within the first 5-30 seconds (may last longer in extreme cold temperatures). The noise is usually more noticeable on the initial start-up when the temperature is below 10°C (50°F) and may be more pronounced on the first cold start following a long trip. This noise may be caused by an interaction between carbon that has formed on the piston, the piston motion and the cylinder wall. GM Powertrain Engineering, and an analysis of engines with this condition, has confirmed that the noise is not detrimental to the performance, reliability or durability of the engine. THIS NOISE DOES NOT HAVE ANY EFFECT ON THE LONGEVITY OF ANY OF THE ENGINE COMPONENTS. Important: At this time, attempts to repair this condition by replacing the engine assembly or pistons are not recommended. Last edited by clinebarger; 01-28-2010 at 05:43 PM.