What would cause my car to be overheating?


Asked by Dec 01, 2012 at 09:11 PM about the 1996 Pontiac Sunfire 2 Dr SE Coupe

Question type: Maintenance & Repair

I have replaced the thermostat(burped the system too), cooling fan motor, and cooling fan relay. I have no
coolant loss. I checked the oil, it is pure oil, but when I pull the dipstick out the oil drips off the dipstick more
than usual for oil to drip off. I can hear a slight chatter in the engine like the internal parts are not getting
lubricated properly. Has anyone ever seen or heard of an engine overheating because the oil went through
thermal breakdown? Could it be that my coolant gauge is faulty, and I need to replace the coolant temp sensor?
I would be doing some voltage and resistance diagnostics if i owned a voltmeter.

12 Answers


Does the coolin fan kick on when it starts toget hot? I have seen a few instances where the water pump starts to wear down and the space increases between the block face and the propeller fins. When this happens the coolant doesn't flow properly and prevents the cooling system from cooling. When does it typically overheat, when parked, highway driving, city driving, or all of the above.

5 of 5 people found this helpful.

Has your radiator ever been replaced or cleaned? Could be the radiator core is getting blocked so coolant is not flowing properly through the engine to pull the heat away from the engine.

3 of 3 people found this helpful.

the coolant fan kicks on. it will overheat at idle, driving down the highway, or stop and go driving. the radiator is good. i was actually thinking about throwing a new water pump on it, along with a fresh oil change. thanks everyone, i'm still open to other ideas though. this one has me pretty stumped.

5 of 5 people found this helpful.

When its cooled off and cold pull the radiator cap off and hit the gas to see if the coolant level lowers in the radiator. Don't over rev it or hold it for too long. Once you release the gas the coolant should come right back up to full.

2 of 2 people found this helpful.

are you using distilled water or tap? tap water tends to leave deposits in the system.; possibly blocking passage ways.

2 of 2 people found this helpful.

also.. some people just use coolant but no water. what is your mix?

3 of 3 people found this helpful.

"good radiator" make sure it not only holds pressure but the fins need to not be full of mud and bugs

1 of 1 people found this helpful.

i will only use distilled water with my mix. its winter where i live so i have a 70% coolant/30% distilled water mix. radiator is completely clean, fins are all good. i'm thinkin i was just a moron and didn't bleed all the air out of the system. again thank you all for the responses. i will update the status of the vehicle tomorrow.

2 of 2 people found this helpful.

distilled h2O is great! your engine will last longer that way. just make sure u open the bleeder valve and pour till coolant starts to bubble out.

Had a similar problem earlier this year. Changed the thermostats and radiator cap to fix problem. It is not a Pontiac but this works on most cars! Good luck!

I'm just a girl so what are you talking about? Once my car ran hot and my brother took the thing that looked like a top hat and cleaned all the leaves and other stuff that had blown in there out then my car cooled again. Do u think this could be it. I am having to take my car to a shop and I don't know what they r going to say. Can u help me?


What is the the thermostat setting for a 2000 pontaic sunfire?

2 of 2 people found this helpful.

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