Engine Overheating
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: The engine temperature lamp comes on and stays on, or temperature gauge shows hot, or coolant overflows from the coolant recovery reservoir onto the ground while the engine is running. Special Tools J-26568 Coolant and Battery Fluid Tester |
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| 1 | Check the condenser, radiator, and auxiliary coolers for any obstructions or bent fins that would prevent air flow through the radiator. Is there any airflow obstruction or bent fins? |
Go to Step 2 | Go to Step 3 |
| 2 |
|
Go to Step 3 | System OK |
| 3 | Check for loose, missing, or damaged radiator air seals or deflectors. Are there any loose, missing, or damaged radiator air seals or deflectors? |
Go to Step 4 | Go to Step 5 |
| 4 | Repair or replace any loose, missing, or damaged radiator air seals or deflectors. Does the engine still overheat? |
Go to Step 5 | System OK |
| 5 | Check for an inoperative cooling fan. Refer to Cooling Fan Inoperative . Is the cooling fan inoperative? |
Go to Step 6 | Go to Step 7 |
| 6 | Repair or replace the cooling fan(s) as necessary. Refer to Engine Coolant Fan Motor Replacement Engine Coolant Fan Motor Replacement (LS7 - Rear) Engine Coolant Fan Motor Replacement (LS7 - Front) . Does the engine still overheat? |
Go to Step 7 | System OK |
| 7 | Check for a loss of coolant. Refer to Loss of Coolant (LFX, L99/LS3, LS7) Loss of Coolant (LSA) . Does the engine still overheat? |
Go to Step 8 | System OK |
| 8 | Check for kinked or pinched cooling hoses. Does the engine still overheat? |
Go to Step 9 | Go to Step 10 |
| 9 |
|
Go to Step 10 | System OK |
| 10 | Using J-26568
Coolant and Battery Fluid Tester , check the coolant concentration. Does the coolant concentration test correctly? |
Go to Step 12 | Go to Step 11 |
| 11 | Replace the coolant, if necessary. Refer to Cooling System Draining and Filling (LFX, Static Fill) Cooling System Draining and Filling (LSA, LS3, LS7, L99 Static Fill) Cooling System Draining and Filling (GE 47716) . Does the engine still overheat? |
Go to Step 12 | System OK |
| 12 | Check for any blocked cooling system passages. Are there blocked cooling system passages? |
Go to Step 13 | Go to Step 14 |
| 13 | Remove any obstructions by flushing the cooling system. Refer to Flushing . Does the engine still overheat? |
Go to Step 14 | Go to Step 19 |
| 14 | Inspect the accessory drive belt tensioner. Refer to Drive Belt Tensioner Diagnosis
, for the 3.6L engine and Drive Belt Tensioner Diagnosis
for the 6.2L engine. Does the engine still overheat? |
Go to Step 15 | System OK |
| 15 | Check for a faulty thermostat. Refer to Thermostat Diagnosis . Does the engine still overheat? |
Go to Step 16 | System OK |
| 16 | Replace the radiator. Refer to Radiator Replacement (LS3, L99) Radiator Replacement (LFX, LSA) Radiator Replacement (LS7 with C42) Radiator Replacement (LS7 with C67) . Does the engine still overheat? |
Go to Step 17 | System OK |
| 17 | Check for a faulty water pump. The impeller blades may be eroded or broken. Is the water pump faulty? |
Go to Step 18 | - |
| 18 | Replace the water pump. Refer to Water Pump Replacement (LS7, LS3/L99) Water Pump Replacement (LFX) Water Pump Replacement (LSA) . Does the engine still overheat? |
Go to Step 19 | - |
| 19 | Operate the system to verify the repair. Did you correct the condition? |
System OK | - |