Engine Overheating. Cadillac Concours 1996

For 1990-2009 cars

Step | Action | Value | 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. 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 . Does the engine still overheat? | -- | Go to Step 3 | System OK
3 | Check for a missing or damaged radiator upper air deflector, baffle, or center air deflector. Are there any missing or damaged deflectors or baffles? | -- | Go to Step 4 | Go to Step 5
4 | Repair or replace any deflectors or baffles as necessary. Does the engine still overheat? | -- | Go to Step 5 | System OK
5 | Check the coolant concentration. Refer to Coolant Concentration Testing . Is the coolant concentration adequate? | -- | Go to Step 7 | Go to Step 6
6 | Correct the coolant concentration as necessary. Refer to Flushing . Does the engine still overheat? | -- | Go to Step 7 | System OK
7 | Check for a loss of cooling system pressure. Does the cooling system maintain the correct pressure? | -- | Go to Step 9 | Go to Step 8
8 | Pressure test the cooling system. Correct as necessary. Refer to Cooling System Leak Testing . Does the engine still overheat? | 103 kPa (15 psi) | Go to Step 9 | System OK
9 | Check for a pinched or kinked radiator surge tank hose. Is the surge tank hose kinked or damaged? | -- | Go to Step 10 | Go to Step 11
10 | Reroute or replace the hose as necessary. Refer to Radiator Surge Tank . Does the engine still overheat | -- | Go to Step 11 | System OK

11

1. Check the drive belt tension. Refer to Drive Belt Diagnosis .
2. Check the tensioner.

Is the tensioner working properly?

--

Go to Step 13

Go to Step 12

12 | Replace the tensioner as necessary. Refer to Accessory Drive Belt Tensioner Replacement in Engine Mechanical. Does the engine still overheat? | -- | Go to Step 13 | System OK
13 | Check for an obstructed radiator air flow or bent fins. Are any radiator fins bent or is air flow to the radiator being obstructed? | -- | Go to Step 15 | Go to Step 14
14 | Check for a blockage in the cooling system passages. Are the cooling system passages blocked? | -- | Go to Step 16 | Go to Step 17
15 | Remove or relocate add on parts that block air flow to the radiator. Refer to Cooling System . Does the engine still overheat? | -- | Go to Step 17 | System OK

16

1. Drain the coolant. Refer to Cooling System Draining and Filling .
2. Flush the cooling system. Refer to Flushing .
3. Repair as necessary.

Does the engine still overheat?

--

Go to Step 17

System OK

17 | Check for an inoperative cooling fan. Refer to Electrical Diagnosis. Are any cooling fans inoperative? | -- | Go to Step 18 | Go to Step 19
18 | Repair or replace the cooling fan as necessary. Refer to Electrical Diagnosis. Does the engine still overheat? | -- | Go to Step 19 | System OK
19 | Check if the thermostat is stuck in the closed position. Refer to Thermostat Diagnosis . Is the thermostat sticking (or stuck) in the closed position? | -- | Go to Step 20 | Go to Step 21
20 | Replace the thermostat as necessary. Refer to Engine Coolant Thermostat Replacement . Does the engine still overheat? | -- | Go to Step 21 | System OK
21 | Check for a faulty coolant pump. Is the coolant pump faulty? | -- | Go to Step 22 | Go to Step 23
22 | Replace the coolant pump as necessary. Refer to Water Pump Replacement . Does the engine still overheat? | -- | Go to Step 23 | System OK
23 | Check the radiator cooling capacity. Make sure the proper sized radiator is being used on the cooling system. Is the correct sized radiator being used with the cooling system? | -- | System OK | Go to Step 24
24 | If necessary, install the correct radiator. Refer to Radiator Replacement . Does the engine still overheat? | -- | -- | System OK