Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 667 (ENGINE COOLING SYSTEM)REPAIR INSTRUCTIONSCOOLANT HEATER REPLACEMENT (3.1 L)INSTALLATION PROCEDURE

1999 GMC Forward Control 5.7 R, Automatic

Installation Procedure

1999 GMC Forward Control 5.7 R, AutomaticSECTION Installation Procedure

WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

Apply a coat of GM P/N 12346004 or equivalent to the following:
- The engine block heater seal
- The cleaned surface of the engine block heater hole
Position the engine coolant heater element at the 3 O'clock position (2).
Install the engine coolant heater.
NOTE: Refer to FASTENER NOTICE .
Tighten the engine coolant heater bolt.
Tighten

Tighten the engine coolant heater bolt to 2 N.m (18 Ib in).
Connect the engine coolant heater cord to the engine coolant heater.
Lower the vehicle.
Fill the cooling system. Refer to Draining and Filling Cooling System .
Inspect for leaks.

Fig 1: Positioning Engine Coolant Heater Element To 3 O'Clock Position
Courtesy of GENERAL MOTORS CORP.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.