GM Service Manual Online
For 1990-2009 cars only

Loss of Coolant (Reseal Coolant Plug/Temperature Sensor)

Subject:Loss of Coolant (Reseal Coolant Plug/Temperature Sensor)

Models:2003 Chevrolet Avalanche, Silverado, Suburban
2003 GMC Sierra, Yukon XL
with 8.1L Engine (VIN G -- RPO L18)



Condition

Some owners may comment on a loss or leakage of coolant. Coolant residue may be found on either cylinder head or appear to be leaking from the cylinder head or gasket.

Cause

The coolant plug or temperature sensor in the head my be leaking.

Correction

Reseal the coolant plug and/or temperature sensor.

  1. Drain the cooling system to below the plug/sensor.
  2. Remove the coolant plug in the right cylinder head and/or the coolant temperature sensor in the left cylinder head.

  3. Object Number: 635678  Size: SH

    Object Number: 470744  Size: SH
  4. After removing the plug and/or sensor, clean the threads.
  5. Apply a coating of thread sealant, P/N 12346004 (Canada P/N 10953480,) to the threads.
  6. Re-install the plug and/or sensor and tighten.
  7. Tighten
    Tighten to 50N·m(37 lb ft).

  8. Refill the coolant to the proper level.

Parts Information

Part Number

Description

12346004

Sealant, Thread (U.S.)

10953480

Sealant, Thread (Canada)

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

J6368

Sensor, Engine Coolant Temperature -- Replace

1.0 hr

Add:

To Do Both

0.1 hr