Engine Overheats or Runs Hot in High Ambient Temperature When Towing or Hauling on Long Inclines (Install 2006 Air Cleaner Assembly)

This bulletin is being revised to clarify steps 10 and 11 and the illustration in step 10 of the procedure. Please discard Corporate Bulletin Number 06-06-04-036C (Section 06 -- Engine/Propulsion System).

Some customers may comment that while towing a trailer, or if the vehicle is loaded on a long upgrade climb and high ambient temperatures, the Driver Information Center states Engine Coolant Hot, the engine overheats and there is a loss of power and air conditioning.

This condition may be caused by any of the following possibilities:

Inspect the following areas FIRST.

If no issues were found after the above inspections, install a 2006 air cleaner system using the following procedure.

1. Disconnect the mass air flow sensor electrical connector and remove the sensor from the air outlet duct.
2. Loosen the clamps and remove the air cleaner outlet duct.
3. Remove the air cleaner assembly. Grasp the air filter assembly and pull up on the assembly in order to disengage the retaining pins from the grommets.
4. Remove the five 10 mm bolts and the tray.
5. Remove the insulation on the inner right fender.



6. With the wheel turned to the right, measure from the corner of the wheel liner over 231 mm (9 in) and up 45 mm (1.8 in) as seen in the illustration above.



7. Measure up 75 mm (3 in) from the bottom of the liner and measure the lip of the liner 20 mm (0.8 in) as seen in the illustration above.
8. With a 5/16 or 8 mm drill bit, drill two holes though the wheelhouse liner.
9. Remove the wheel liner fasteners and pull the liner back.



10. Install the new baffle assembly intake air (lower baffle) to the fender with the two push-in fasteners. The arrows in the illustration above point to where the push-in fasteners will go.



11. Install the new inner fender air duct by inserting the duct between the inner and outer sheet metal. The duct has a nipple on the side and will snap in place on the inner sheet metal of the fender.
12. Install the wheel liner and fasteners.
13. Install the two bolts that retains the baffle assembly intake air to the wheel liner.
14. Install the plastic closeout panel on the radiator support.
15. Install the air cleaner bracket, bolts and new tray.

Tighten
Tighten the bolts to 9 N·m (80 lb in).

16. Install the air cleaner assembly. Push down on the assembly in order to secure it to the bracket.




Notice: Do not attempt to cut off the outlet duct on the vehicle or debris could enter the turbo and cause damage.

17. Measure back from the Caution label on the air cleaner outlet duct 52 mm (2 in) on the existing duct, and cut the duct.



18. Measure from the side that was cut, 13 mm (½ in), and drill a 5/32 or 5 mm hole on each side of the duct and install rivets as seen in the illustration above.
19. Connect the two ducts together.
20. Install the air cleaner outlet duct to the air cleaner assembly and the turbo inlet. It may be necessary to reposition the clamp on the air cooler outlet duct.

Tighten
Tighten the three clamps to 4 N·m (35 lb in).

Tighten
Tighten the air cooler outlet duct clamp to 6 N·m (53 lb in).

21. Install the mass air flow sensor and connect the connector.



22. Install the intake horizontal baffle as seen in the illustration above.



23. Remove the right head lamp assembly. Refer to SI if necessary. With the head lamp out, clean the surface with 3M® General Purpose Adhesive Cleaner, or equivalent. Install the baffle intake air (foam block) on the radiator support as seen in the illustration above.
24. Reprogram the vehicle PCM with new software. Refer to TIS for the calibration cylindrical air cleaner housing.
25. Reposition the engine oil indicator (dipstick) tube toward the fender so it will clear the air cleaner outlet duct.

If the vehicle is a 2004 or 2005 GMC Sierra, the following items will have to be installed to ensure cooler air is entering the system.

1. Remove the left and right head lamp assembly. Refer to SI if necessary.
2. Install the seal around the lamp with the wide part of the seal across the top of the lamp.
3. Remove the grille. Refer to SI if necessary.



4. Install the seals on the left and right side of the grille as seen in the illustration above.



5. Clean the surface of the inner right fender and install the vertical seal as seen in the illustration above.
6. Clean the lip on the left fender and install the horizontal hood seal to the fender.
7. Install the grille.
8. Install the head lamps. Refer to SI if necessary.

Important: Ensure that the sealing is optimized between the air cleaner housing and the inner fender.

For vehicles repaired under warranty, use: