shooterutting

i have a 2000 chevy with a 5.3 vortec i have a knock noise coming from the motor but i cant locate it. it happend one day then stoped for a week now its back. its really loud the truck runs fine and i still have good oil pressure a rod knock or lifter tick wouldnt just come and go like that so i dont know what if could be PLEASE HELP

swift81

I have had a rod knock that comes and goes depending on temperature and how hard I drive it. It has been there for about 75,000 miles now and still has good oil pressure and runs fine. I think switching to synthetic 5W30 seems to have helped.

JuniorCar

Do those things have electric fan clutches?

MDTAHOE

It would be hard for anyone to truly help you without hearing it. Pull up to any shop (maybe at a gas station) ask them to listen. There should not be any charge for that. You could go to several and get may opinions. If there is a general consensus they are probably right.

Lady3bglover

A while back I was dealing with the same issue, and I found out that GM actually had a recall on the knock sensors. My truck was still under warranty at the time, so it was covered. Sorry if this is TMI.. but at least it's a head start. G/L

Here is the bulletin


Bulletin No.: 02-06-04-023A

Date: June, 2002

TECHNICAL

Subject:
Audible Spark Knock (Detonation), MIL Illuminated, DTC P0332 Set (Replace Rear Bank Knock Sensor and RTV Area Around Sensor)

Models:
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, L09, L04)

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.

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

2. Remove the wiring harness assembly from the knock sensor.

3. Remove the rear bank knock sensor.

4. Install the new rear bank knock sensor.

Tighten

Tighten the knock sensor to 20 N.m (15 lb ft).

5. Install the wiring harness assembly to the knock sensor.

6. 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.

7. From the underside of the intake manifold, completely remove the rear intake manifold seal (foam material).

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