OEM GMC Sierra 1500 Classic Thermostat

GMC Sierra 1500 Classic Thermostat Parts Questions & Experts Answers

• Thermostat
  89018168
  Q: How to replace the thermostat on a 4.3L engine on GMC Sierra 1500 Classic?

  A:

  Begin by draining the cooling system to replace the Thermostat on a 4.3l engine. Loosen the air cleaner outlet duct clamp on the mass airflow/intake air temperature (MAF/IAT) sensor, then, remove the positive crankcase ventilation (PCV) hose and the air cleaner adapter nut. Lift up the air cleaner outlet duct till the hinge clip is released from the lip within the Throttle Body hence repositioning the inlet hose clamp to the water outlet and taking off the inlet hose. Next, take out the water outlet studs and the water outlet and then the Thermostat. Clean sealing surfaces of both water outlet and Intake Manifold and throw the old o-ring seal. For installation, fit a new o-ring seal on the Thermostat and install it, then the water outlet. Install the water outlet studs and tighten them to 25 nm (18 ft. Lbs.). Reconnect the inlet hose to the water outlet and the location of the inlet hose clamp. The second step is to slide the bolt through the hole, align the hinge clip with the Throttle Body lip and turn the air cleaner outlet duct down into the position where the nut mount goes onto the air cleaner adapter and the pcv hose. Tighten the clamp of the air cleaner outlet duct on the maf/iat sensor to 4 nm (35 inch lbs.). Finally, fill up the system for cooling and check for leaks.