slight knock/ping during acceleration

[gwinters]

I have a 2001 1500, 2WD Sub. w/ a 5.3L eng. When accelerating through the RPM range of 1400 to about 1600 there is a slight knock in the engine. It is not too loud, in fact it is much like the sound you expect when you bought bad gas. I have since started using better gas, even added gas treatment, some octane boost, etc. But the problem persists. Anyone have any ideas? Someone has suggested looking into a flash upgrade for the computer, thinking possibly the computer is running the engine too lean at that RPM. Does that sound feasible? If so what does this sort of thing cost?

Thanks in advance...

[99ssconv]

Audible Spark Knock (Detonation), MIL Illuminated, DTC P0332 Set (Replace Rear Bank Knock Sensor and RTV Area Around Sensor) #02-06-04-023A - (06/14/2002)
Audible Spark Knock (Detonation), MIL Illuminated, DTC P0332 Set (Replace Rear Bank Knock Sensor and RTV Area Around Sensor)
1998-2002 Chevrolet Camaro, Corvette

1998-2002 Pontiac Firebird

with 5.7L Engine (VIN G -- RPO LS1)

1999-2002 Chevrolet Silverado, Suburban, Tahoe

2002 Chevrolet Avalance

1999-2002 GMC Sierra, Yukon, Yukon XL

2002 Cadillac Escalade, Escalade EXT

with 4.8L, 5.3L or 6.0L Engine (VINs V, T, Z, N, U -- RPOs LR4, LM7, L59, LQ9, LQ4)

This bulletin is being revised to add Cadillac Escalade and Cadillac Escalade EXT to the Models. Please discard Corporate Bulletin Number 02-06-04-023 (Section 6 -- Engine/Propulsion System).

Condition
Some customers may comment on a mild to severe engine ping (commonly referred to as spark knock), usually worse during acceleration and/or an illuminated MIL. Upon investigation, the technician may find DTC P0332 set.

Cause
This condition may be the result of corrosion of the rear bank knock sensor due to water intrusion into the sensor cavity. This condition is more apparent on vehicles in which customers frequently wash the engine compartment.

Correction
Replace the rear bank knock sensor and build a dam (wall) around the sensor using RTV to divert water away from the sensor. Use the procedure and part number listed below.

Remove the intake manifold. Refer to the Intake Manifold Replacement procedure in the Engine Controls sub-section of the appropriate Service Manual.



Remove the wiring harness assembly from the knock sensor.



Remove the rear bank knock sensor.
Install the new rear bank knock sensor. Tighten
Tighten the knock sensor to 20 N·m(15 lb ft).

Install the wiring harness assembly to the knock sensor.



Apply a bead of RTV silicone sealant approximately 9 mm (3/8 in) wide and 6 mm (1/4 in) high along the outside edge of the ridge on the engine block valley cover around the rear bank knock sensor. DO NOT form a complete circle. Leave the rear section open as shown.
From the underside of the intake manifold, completely remove the rear intake manifold seal (foam material).
Install the intake manifold. Refer to the Intake Manifold Replacement procedure in the Engine Controls sub-section of the appropriate Service Manual.
Parts Information
Part Number
Description
Qty

10456603
Sensor, Knock
1


Parts are currently available from GMSPO.