Overheating

1983 CHEVROLET IMPALA

140,000 MILES • 3.8L • 6 CYL • 2WD • AUTOMATIC

SOCALSMOKE

MEMBER
2 POSTS

New water pump, new radiator and cap, new temperature sensor. New cooling fans they both come on with the A/C and when the car gets warm on their own correctly. A/C relays okay, no exhaust gases in the radiator confirmed with chemical test. new thermostat no leaks anywhere that I can see. no white smoke in the tailpipe. heater works excellent except on the passenger side A/C works great on both sides until the temperature gauge gets to about half then it blows warm. I can't think of anything else to check. what am I missing here? if I turn the A/C off it'll cool off a little bit then right back up. when I turn the air on again but will still overheat whether the A/C is on or not.

Jul 23, 2021 at 9:40 AM

JACOBANDNICKOLAS

✓Experienced Mechanic
110,240 POSTS

Hi,

Do the cooling fans come on when the A/C is turned on regardless of engine temperature? If you are driving at highway speeds, will the engine overheat? When this happens, is there ever steam from the engine or a boiling sound that would indicate the engine is actually overheating?

Take a look through this link and let me know if anything mirrors what you experience:

https://www.2carpros.com/articles/symptoms-of-a-bad-coolant-temperature-sensor

Let me know.

Joe

Jul 23, 2021 at 3:47 PM

SOCALSMOKE

MEMBER
2 POSTS

Yes, fans come on with A/C regardless of engine temperature. The coolant temperature sensor is new also. no specific speeds just once it reaches engine temperature it just keeps going up. Never actually overheats all the way, temperature gauge got to 3/4 once but usually once it's at half I turn the heat on until it gets back to operating temperature. No steam no boiling.

Jul 26, 2021 at 6:25 AM

JACOBANDNICKOLAS

✓Experienced Mechanic
110,240 POSTS

Hi,

I'm questioning if the PCM isn't reading the temp sensor correctly. Do you have access to an infrared thermometer? I'm curious to see if the gauge in the vehicle is accurate. Did the original temperature sensor function the same as this one?

Also, this vehicle has a 2bbl carburetor, correct? Do you notice any exhaust smell that may indicate a rich mixture? Has the ignition timing been checked using a test light?

Let me know.

Joe

Jul 26, 2021 at 11:36 AM

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