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Home >> GMC >> 2006 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1539 (Engine Cooling System - Non-Hybrid) >> Diagnostic Information and Procedures >> Engine Overheating

Engine Overheating

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Step Action Yes No
1 Inspect for a missing or damaged radiator side or upper baffle and/or radiator air deflector.
Is the baffle and/or deflector missing or damaged?
Go to Step 8  Go to Step 2 
2 Inspect for a loss of coolant.
Is there a loss of coolant?
Go to Step 3  Go to Step 4 
3 Fill the system to the specified level.
Does the engine overheat?
Go to Step 4  System OK
4 Inspect for low temperature protection.
Is the coolant to the correct concentration?
Go to Step 5  Go to Step 8 
5 Inspect for a loss of cooling system pressure.
Is there a loss of system pressure?
Go to Step 8  Go to Step 6 
6 Inspect for a faulty engine coolant temperature (ECT) sensor. Refer to DTC P0117 or P0118 (Without L96) .
Is the sensor operating properly?
Go to Step 7  Go to Step 8 
7 Inspect for the following:
  • Damaged coolant surge tank
  • Leaking hose
  • Bad/incorrect surge tank or radiator cap

Were any of the above found?
Go to Step 8  Go to Step 3 
8 Repair or install new parts as necessary, then retest.
Does the engine overheat?
Go to Step 9  System OK
9 Inspect for incorrect drive belt tension.
Is the belt tension correct?
Go to Step 10  Go to Step 8 
10
  1. Remove the water pump. Refer to Water Pump Replacement (LU3)  or Water Pump Replacement (LMM)  or Water Pump Replacement (V8) .
  2. Inspect for a damaged water pump shaft/hub.
Is the water pump driveshaft damaged or is the seal leaking?
Go to Step 8  Go to Step 11 
11 Inspect for obstructed radiator air flow or bent radiator fins.
Is the radiator air flow obstructed?
Go to Step 8  Go to Step 12 
12 Inspect for blocked cooling system passages.
Are the cooling system passages blocked?
Go to Step 8  Go to Step 13 
13 Inspect the thermostat. Refer to Thermostat Diagnosis .
Is the thermostat stuck in the closed position?
Go to Step 15  Go to Step 16 
14 Replace the thermostat. Refer to Engine Coolant Thermostat Housing Replacement (LFA,LH6, LMG,LY2, LY5,LY6) .
Does the engine overheat?
Go to Step 16  System OK
15 Inspect the radiator cooling capacity.
Is the proper sized radiator being used on the vehicle?
Go to Step 3  Go to Step 17 
16 Consult the current parts catalog and replace the radiator. Refer to Radiator Replacement (LMM)  or Radiator Replacement (4.3L, 4.8L, 5.3L, and 6.0L) .
Is the repair complete?
System OK -