Need help with a car problem.

[iamwiz82]

My girlfriend's 1995 Cutlass Ciera 3.1L is giving me problems. Yesterday, i went to take it to out and within 3 miles, the car overheated. No big deal, i saw the coolant was low so i filled with a 50/50 mix. I ran it again, and it did the same thing. This time, i was too far from home to drive back on, so i let it cool for 15 min and put on the heater full blast. I started to drive back and it overheated again, but the heater was NOT blowing hot air, it was cold.

I tried it again this morning and it did the same thing, but after letting the car sit with the engine on for about 15 min after overheating, the heater started blowing hot air. The temp dropped to normal level and i started driving home. About 3 miles later, the air went cold again and the car overheated.

I assumed that when the thermostat was stuck closed, i would still be getting hot air through the heater, yes?

 

[toph99]

did you check the water pump?

 

[iamwiz82]

Originally posted by: toph99
did you check the water pump?

i'm hoping it is something smaller than that

 

[pyonir]

does the fan come on? (not the fan for the heater/ac)

 

[iamwiz82]

Originally posted by: pyonir
does the fan come on? (not the fan for the heater/ac)

yes, it does.

 

[Beau]

Could also just be a clogged/blocked thermostat. Pretty easy to replace. But my money is on the pump.

 

[pyonir]

check all the hoses to make sure there are no cracks. if they are all good, then my guess is water pump.

 

[iamwiz82]

Originally posted by: pyonir
check all the hoses to make sure there are no cracks. if they are all good, then my guess is water pump.

i would assume that there are no cracks after a quick inspection, because the car is not leaking anything.

 

[XZeroII]

Has the coolant gone down at all? I would say thermostat or water pump. Thermostat is usually a small cheap and easy to replace part so I would try that first. Is the engine actually getting hot? or are you just going by the guage?

 

[iamwiz82]

Originally posted by: XZeroII
Has the coolant gone down at all? I would say thermostat or water pump. Thermostat is usually a small cheap and easy to replace part so I would try that first. Is the engine actually getting hot? or are you just going by the guage?

the coolant has not gone down. Let me put it this way, i can touch the hose running from the thermostat to the radiator after it overheats and it is not hot.

 

[Beau]

Originally posted by: iamwiz82

Originally posted by: XZeroII Has the coolant gone down at all? I would say thermostat or water pump. Thermostat is usually a small cheap and easy to replace part so I would try that first. Is the engine actually getting hot? or are you just going by the guage?

the coolant has not gone down. Let me put it this way, i can touch the hose running from the thermostat to the engine after it overheats and it is not hot.

Your thermostat is on the engine block. It's a little metal diaphram that stops or allows the flow of coolant into/out of the engine depending on the heat. So if your hose is cold between your radiator and your engine, then that means the flow of coolant is not happening. Again this could be caused by a faulty/blocked thermostat or a faulty water pump.

 

[iamwiz82]

Originally posted by: Beau6183

Originally posted by: iamwiz82

Originally posted by: XZeroII Has the coolant gone down at all? I would say thermostat or water pump. Thermostat is usually a small cheap and easy to replace part so I would try that first. Is the engine actually getting hot? or are you just going by the guage?

the coolant has not gone down. Let me put it this way, i can touch the hose running from the thermostat to the engine after it overheats and it is not hot.

Your thermostat is on the engine block. It's a little metal diaphram that stops or allows the flow of coolant into/out of the engine depending on the heat. So if your hose is cold between your radiator and your engine, then that means the flow of coolant is not happening. Again this could be caused by a faulty/blocked thermostat or a faulty water pump.

i know, the tube that runs from the thermostat housing to the radiator

 

[Beau]

Okay, you said "the hose running from the engine to the thermostat" so I just wanted to make sure I/you wasn't/weren't confused. But my answer still sits

 

[iamwiz82]

oh, whoops, i'm editing now.


anyone have any reason why the heater would blow cold, then hot and then cold?

 

[Beau]

Originally posted by: iamwiz82
oh, whoops, i'm editing now. anyone have any reason why the heater would blow cold, then hot and then cold?

You have a secondary radiator called the heater core that runs in parallel with your cooling system. If your coolant is not circulating through your cooling system, then it is not getting to your heater core either. Same reasons can cause this. Your pump could have started up and then stopped again, or maybe your thermostat opened for a little while...

 

[iamwiz82]

i know about the heater, but i couldn't imagine the pump or thermostat not working, then working and then not working.

 

[KennyH]

If the upper radiator hose is not hot when the car overheats then it is most likely a stuck thermostat. Sometimes they can work and other times they don't. This could easily explain the hot/cold/hot effects. Most are easy to replace and only cost around $6-$8 dollars for a lifetime warranty one.

 

[Beau]

Originally posted by: iamwiz82
i know about the heater, but i couldn't imagine the pump or thermostat not working, then working and then not working.

Just stop you complaining and try the thermostat. If that doesn't work then it is probably the water pump.

 

[iamwiz82]

it is supposed to rain this evening, and i have no garage

 

[Squisher]

Originally posted by: iamwiz82
i know about the heater, but i couldn't imagine the pump or thermostat not working, then working and then not working.

With a thermostat happens, plenty. Never heard of a water pump going out and coming back, maybe if some are electric.

 

[KennyH]

Try the thermostat and if it doesn't work, it prolly is the water pump.

 

[Beau]

Originally posted by: iamwiz82
it is supposed to rain this evening, and i have no garage

Wuss! Just don't put your hand on the positive battery terminal.

 

[Squisher]

In a pinch you could run without a thermostat, but the car will run hot because the water will rush through the radiator before it can cool down.