Engine Overheating

2006 Chevrolet Cobalt SS, 4D Sedan, StandardSECTION Engine Overheating
WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
Step Action Value(s) Yes No
DEFINITION: The engine temperature lamp comes ON and stays ON, or the temperature gauge shows hot, or coolant overflows from the surge tank onto the ground while the engine is running.
1 Check for a loss of coolant. Refer to Loss of Coolant .
Is there a loss of coolant?
- Go to Step 2  Go to Step 3 
2 Fill the system to the specified level. Refer to Cooling System Draining and Filling (Static Fill LE5, L61)  or Cooling System Draining and Filling (Static Fill LNF)  or Cooling System Draining and Filling (GE 47716 Fill) .
Does the engine still overheat?
- Go to Step 3  System OK
3 Check for kinked or pinched surge tank hoses, especially at the radiator.
Are any surge tank hoses kinked or pinched?
- Go to Step 4  Go to Step 5 
4
  1. Relieve any kinks by rerouting the hoses.
  2. Replace the hoses if necessary.
Does the engine still overheat?
- Go to Step 5  System OK
5 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 6  Go to Step 7 
6 Repair or replace any loose, missing, or damaged radiator air seals or deflectors. Refer to Radiator Air Side Baffle and Deflector Replacement  or Radiator Air Upper Baffle and Deflector Replacement .
Does the engine still overheat?
- Go to Step 7  System OK
7 Check the coolant concentration.
Does the coolant concentration test correctly?
- Go to Step 9  Go to Step 8 
8 Replace the coolant if necessary. Refer to Cooling System Draining and Filling (Static Fill LE5, L61)  or Cooling System Draining and Filling (Static Fill LNF)  or Cooling System Draining and Filling (GE 47716 Fill) .
Does the engine still overheat?
- Go to Step 9  System OK
9
NOTE: Use the correct pressure cap.
Check the system for loss of pressure.Is there a loss of pressure?
- Go to Step 10  Go to Step 11 
10 Repair any leaks as necessary.
Does the engine still overheat?
- Go to Step 11  System OK
11 Check for a faulty engine coolant temperature (ECT) sensor.
Is the engine coolant temperature sensor faulty?
- Go to Step 12  Go to Step 13 
12 Replace the ECT. Refer to one of the following:
Does the engine still overheat?
- Go to Step 13  System OK
13 Check the radiator for any airflow obstructions or bent fins.
Is there any airflow obstruction or bent fins?
- Go to Step 14  Go to Step 15 
14
  1. Remove or relocate add-on parts that block airflow to the radiator.
  2. Clean any debris from the radiator core.
Does the engine still overheat?
- Go to Step 15  System OK
15 Check for any blocked cooling system passages.
Are there any blocked cooling system passages?
- Go to Step 16  Go to Step 17 
16
  1. Remove any obstruction.
  2. Flush the cooling system as required. Refer to Coolant System Flushing .
  3. Refill the coolant. Refer to Cooling System Draining and Filling (Static Fill LE5, L61)  or Cooling System Draining and Filling (Static Fill LNF)  or Cooling System Draining and Filling (GE 47716 Fill) .
Does the engine still overheat?
- Go to Step 17  System OK
17 Check for an inoperative cooling fan.
Is the cooling fan inoperative?
- Go to Step 18  Go to Step 19 
18 Replace the cooling fan. Refer to Cooling Fan and Shroud Replacement .
Does the engine still overheat?
- Go to Step 19  System OK
19 Check for a thermostat that is stuck closed.
Is the thermostat stuck closed?
- Go to Step 20  Go to Step 21 
20 Replace the thermostat. Refer to Engine Coolant Thermostat Replacement (LNF) .
Does the engine still overheat?
- Go to Step 21  System OK
21 Check for a faulty water pump. The impeller blades may be eroded or broken.
Is the water pump faulty?
- Go to Step 22  -
22 Replace the water pump. Refer to Water Pump Replacement (LNF) .
Does the engine still overheat?
- - System OK
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.