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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Cavalier 🢒 Engine 🢒 Engine Cooling 🢒 Engine Overheating

Engine Overheating Diagnosis

Step

Action

Value

Yes

No

DEFINITION: Engine temperature lamp comes on and stays on, or temperature gauge shows hot, or coolant overflows from the surge tank onto the ground while the engine is running

1

Test for a loss of coolant. Refer to Loss of Coolant .

Do you notice 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 .

Does the engine still overheat?

--

Go to Step 3

System OK

3
  1. Inspect the surge tank hoses for kinks or pinches, especially at the radiator.
  2. Relieve any kinks by re-routing the hoses. Replace the hoses if necessary.

Does the engine still overheat?

--

Go to Step 4

System OK

4
  1. Inspect for loose, missing or damaged radiator air seals or deflectors.
  2. Repair or replace the part(s) as necessary. Refer to Radiator Air Baffle Assemblies and Deflectors .

Does the engine still overheat?

--

Go to Step 5

System OK

5

Test the coolant concentration. Refer to Coolant Concentration Testing .

Does the engine still overheat?

--

Go to Step 6

System OK

6
  1. Test the system for loss of pressure.
  2. Do a system pressure test. Refer to Cooling System Leak Testing .
  3. Verify that the correct pressure cap is being used.

Does the engine still overheat?

--

Go to Step 7

System OK

7

Test for a faulty Engine Coolant Temperature (ECT) sensor. Refer to Engine Controls.

Does the engine still overheat?

--

Go to Step 8

System OK

8
  1. Test the radiator for any air flow obstruction.
  2. Test the radiator for bent fins.
  3. Remove or relocate add-on parts that block air flow to the radiator.
  4. Clean any bugs, leaves, or snow from the radiator core.

Does the engine still overheat?

--

Go to Step 9

System OK

9
  1. Inspect for blocked cooling system passages.
  2. Remove any obstruction. Flush the cooling system as required. Refer to Flushing .
  3. Refill the coolant. Refer to Cooling System Draining and Filling .

Does the engine still overheat?

--

Go to Step 10

System OK

10
  1. Test for an inoperative cooling fan. Refer to Electrical Diagnosis.
  2. Repair as necessary.

Does the engine still overheat?

--

Go to Step 11

System OK

11
  1. Inspect for a stuck closed thermostat. Refer to Thermostat Diagnosis
  2. Replace the thermostat as necessary. Refer to Engine Coolant Thermostat Replacement .

Does the engine still overheat?

--

Go to Step 12

System OK

12
  1. Test for a faulty coolant pump. The impeller blades may be eroded or broken.
  2. Replace the coolant pump as necessary. Refer to Water Pump Replacement .

Is the repair complete?

--

System OK

--

Engine Overheating Check

  1. Does overheating occur while pulling a trailer?
    2. • Is the trailer within the recommended towing payload?
    • Is the vehicle equipped with a heavy duty cooling package?
  2. Is the vehicle equipped with an add-on, or aftermarket, air conditioning system? If so, was a heavy duty radiator installed?
  3. Is overheating occurring after prolonged idle in gear with the A/C system operating?
  4. Is overheating occurring after prolonged driving in slow city traffic, or traffic jams?

If any of the above conditions apply, instruct the operator on driving techniques that would reduce the possibility of engine overheating.

If none of the above conditions apply, refer to Engine Overheating .