GM Service Manual Online
For 1990-2009 cars

Grind and/or Rattle Noise from Engine Front Cover Area

Subject:Grind and/or Rattle Noise from Engine Front Cover Area (Replace Timing Chain Assembly, Tensioner and Guides)

Models:1993 Saturns built between and including VINs PZ233317 to PZ293164, equipped with DOHC (LLO) and SOHC (LKO) engines.



Condition

Some customers may comment about a grind and/or rattle noise coming from the engine compartment under all operating conditions. The noise is more evident near the engine front cover with the hood open.

Cause

On these vehicles, the oil bleed hole on the timing chain tensioner assembly was increased from 1 mm to 1.6 mm. The increased bleed hole size may cause the timing chain tensioner assembly plunger to seize and/or stick in the timing chain tensioner assembly plunger bore. This may cause premature wear of the timing chain assembly and timing chain guides, causing a grind and/or rattle noise.

Important: The illustration on the next page shows the difference between the 1 mm and 1.6 mm oil bleed hole.

Correction

Perform the following procedure to repair the condition


Object Number: 877884  Size: MF

Procedure:

  1. For DOHC (LLO) engines, remove the camshaft cover and inspect the timing chain assembly-to-upper timing chain guide. The timing chain assembly should be tight against the upper timing chain guide.
  2. If the timing chain assembly is not tight against the upper timing chain guide, replace the timing chain assembly, timing chain tensioner assembly and three timing chain guides, (Refer to "Front Cover - in - Chassis" procedure in the "1991 - 1994 Engine Mechanical Service Manual.")

    If the timing chain assembly is tight against the upper timing chain guide, refer to the appropriate diagnosis in the "1991 - 1994 Engine Mechanical Service Manual."

  3. For SOHC (LKO) engines, remove the valve rocker arm cover and inspect the tightness of the timing chain assembly on the camshaft sprocket. The timing chain assembly should be tight around the camshaft sprocket.
  4. If the timing chain assembly is not tight around the camshaft sprocket, replace the timing chain assembly, timing chain tensioner assembly and two timing chain guides. (Refer to "Front Cover - In - Chassis" procedure in the "1991 - 1994 Engine Mechanical Service Manual.")

    If the timing chain assembly is tight around the camshaft sprocket, refer to the appropriate diagnosis in the "1991 - 1994 Engine Mechanical Service Manual."

Parts Requirements

DOHC (LLO) ENGINE

21000336

Chain Asm - Tmg

21000339

Guide - Tmg Chain

21006035

Guide - Tmg Chain

21006435

Guide - Tmg Chain

SOHC (LKO) ENGINE

21000096

Chain Asm - Tmg

21000099

Guide - Tmg Chain

21006498

Guide - Tmg Chain

 

DOHC (LLO) AND SOHC (LKO) ENGINES

21006504

Tensioner Asm - Tmg Chain

Claim Information

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System as follows:

Case Type

Description

Labor Operation Code

Time

VW

Replace Timing Chain, Timing

T9665

3.9 hrs

 

Chain Guides and Timing

Chain Tensioner

Assembly -- DOHC (LLO)

Engines

Add:

To replace camshaft cover gasket, if necessary

0.5 hrs

VW

Replace Timing Chain, Timing

T9665

3.6 hrs

Add:

With P/S

0.3 hrs

To replace rocker cover gasket, if necessary

0.3 hrs