Pontiac Sunfire engine overheating

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crystal37
Pontiac Sunfire engine overheating

Post by crystal37 » Wed Jan 01, 2014 12:46 pm

I have a 1999 Pontiac sunfire. 2.2L engine. It was overheating the other morning, I had the water pump replaced, and the thermostat which helped some. still running hot though. I also have no heat in the car now, but after replacing the water pump the heat came and went and now there is none at all. had smoke coming through the defrost vent last time I drove it. haven't drove it since then cause Im not sure what needs to be replaced. I know my coolant tank is full of rusty color and there was rust in my thermostat bad. I may need just a simple flush but wondering if I need to also replace my heater core. there is no sign of leaking in the floor board but last time I drove it, it used a lot of coolant. anything would help.... thank you.

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butch
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Re: Pontiac Sunfire engine overheating

Post by butch » Thu Jan 02, 2014 5:05 pm

The fact that the heat comes and goes on your Cavalier means that the coolant is low or there are air pockets in the system.
You say that is used a lot of coolant, so your either have a leak or it is burning.

Steam or smoke from the defrost vents means a leaking heater core. If there is none on the floor, that i cannot see that being the cause of your loss of a large amount of coolant. Wipe your finger on the base inside of the windshield to see if it feels greasy, if so, then the heater core is leaking. If not, then you have another problem.

You may have a blown headgasket. That would explain the loss of coolant and the heat coming and going. Remove the spark plugs and look for signs of burning coolant.
The fact that the heat comes and goes on your Cavalier means that the coolant is low or there are air pockets in the system.
You say that is used a lot of coolant, so your either have a leak or it is burning.
Spark Plug Inspect

Xander
Posts:14
Joined:Thu Mar 12, 2015 2:34 am

Re: Pontiac Sunfire engine overheating

Post by Xander » Wed Jun 03, 2015 4:13 pm

Air leaks into the coolant chanel and further deteriorating engine cooling effect.

cbcurtis
Posts:1
Joined:Thu Jun 06, 2019 8:45 pm

Re: Pontiac Sunfire engine overheating

Post by cbcurtis » Thu Jun 06, 2019 8:50 pm

I have the same issue in my 2000 Sunfire. I have already dropped in 2nd engine which also overheated and blew head gasket. Before I drop engine number 3 in why does it keep overheating and blowing head gaskets. Help!

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