Engine - Knocking Noise Betweeen 800 to 1400 RPM

BULLETIN NUMBER:
01-003-00R

DATE:
March 9, 2000

REVISED:
04/25/00

MODELS:
1999 626

SECTION:
01

SUBJECT:
ENGINE KNOCKING NOISE FROM 800-1400 RPM

BULLETIN NOTE
This bulletin supersedes 01-003/00. The torque values in the REPAIR PROCEDURE have changed.


APPLICABLE MODEL(S)/VINS
All 1999 626 with V6 (KL) engine.


DESCRIPTION
Some vehicles may exhibit an engine knock noise that can be heard outside the vehicle at approximately 800 - 1400 RPM after the engine reaches operating temperature. It may also be heard inside the vehicle with the windows rolled up and all accessories OFF. The knock may sound like a lower end noise from a rod or main bearing This concern may be caused by incorrect adjustment of the drive belts. In most cases, excessive power steering water pump belt tension combined with lower tension of the AC/generator drive belt causes the noise. Customers having this concern should have their vehicle repaired using the following procedure.


REPAIR PROCEDURE
1. Verify customer concern:

- Start engine and allow it to run for several minutes after reaching operating temperature.

- Listen for knock noise with the hood raised and slightly accelerating the engine. This noise may also be heard inside the vehicle with brakes applied, transmission in gear and lightly accelerating the engine.





2. Check the bolts securing the idler pulley bracket assemblies to the engine block. Tighten if necessary

Tightening torque
1.9-2.6 kgf-m (14-18 ft-lbf)

3. Adjust power steering/water pump drive belt tension as follows:

A. Loosen locknut A.

B. Using adjusting bolt B, adjust belt tension.

Recommended belt tension

40-50 kgf (88-110 lbf)

C. After belt tension is adjusted, retighten locknut A.

Tightening torque

3.2-4.7 kgf-m (24-33 ft-lbf)





4. Adjust generator/NC drive belt tension as follows:

A. Slightly loosen the locknut C.

B. Start engine.

C. With engine running, begin increasing the belt tension using the adjusting bolt D.

D. Increase belt tension until knocking noise is no longer heard while lightly accelerating the engine.

Recommended belt tension
60-70 kgf (132-154 lbf)

E. Retighten locknut C.

Tightening torque
3.2-4.7 kgf-m (24-33 ft-lbf)

5. Verify repair.

WARRANTY INFORMATION

Note
This information applies to verified customer complaints on vehicles covered under normal warranty. Refer to the SRT microfiche for warranty term information.

Consumer Notice: