97 aspire overheated for the first time and i have some questions

[damac]

i searched allot and have the haynes manual, which also mentions the later cars have some computer controlled stuff that might need to be looked at by a tech.

after trying to look things over i just had some generic questions.

its 100+ here in the summer. i was driving about a half an hour then rolled into a parking lot and parked, sat idle for 5 minutes with the blower on high. that is when i noticed stinky smoke and a bunch of coolant under the drivers side tire.

during 5 minutes, then me popping the hood and looking around for busted hoses, etc. i noticed the radiator fan never came on, and has not come on since. i jumped it to the battery and it works fine.

1. is it possible that something simple like a tweaked thermostat would tell the computer not to turn the radiator fan on?

2. does it sound right that i could overheat a car in those conditions if working normally, but without that radiator fan?(i know in the past i would always here this fan come on when sitting at lights, etc. it overpowers the engine noise)

3. i am going to flush the radiator system for sure, and i was thinking of blindly getting a new thermostat to replace(it has never been done), just to see if it perhaps magically starts working again?

maybe wishfull thinking but i thought it would be a good starting point.

4. i have never had this cars temp gauge go past just a tad over the halway point. during this overheat it did not go any higher either than the typical reading i get when warmed up on a hot day like this.

if it were cold out, it would take 10+ minutes for the reading to be effected from the bottom point and would never reach the halfway mark on the gauge.

also during the overheat both upper and lower radiator hoses were hot as hell. if i idle the car now in the same heat with the hood up both upper and lower are warm. if i warmup the car at night for 10 minutes, the top one gets warm but the lower does not.

also i can turn on the car and turn on the heater full blast and there is warm air when its hot out, which gets hotter as the car warms up. if its cold outside it is cold air until the engine warms up a bit, then it comes out hot.


thanks for any thoughts!

[2ndmouse]

I had a 96 aspire, IIRC there is a temp sensor that kicks on the fan. If thats gone bad the fan wont come on.

If I was you, I'd put in a new sensor and a new thermostat (overheating sometimes ruins them, not always but I'd get a new one) and see if it heats up and if you possibly warped the head.

Check your oil for water contamination and check the radiator for oil contamination, a sign you have a breached head gasket. (from overheating/warping)

I overheated my 96 once pretty badly, a new sensor fixed it and no damage was done. I hope you are as lucky.

[mechanicaldj]

overheating your car now, can give you problems 50,000 - 100,000 miles later

[TominMO]

i searched allot and have the haynes manual, which also mentions the later cars have some computer controlled stuff that might need to be looked at by a tech.

after trying to look things over i just had some generic questions.

its 100+ here in the summer. i was driving about a half an hour then rolled into a parking lot and parked, sat idle for 5 minutes with the blower on high. that is when i noticed stinky smoke and a bunch of coolant under the drivers side tire.

during 5 minutes, then me popping the hood and looking around for busted hoses, etc. i noticed the radiator fan never came on, and has not come on since. i jumped it to the battery and it works fine.

1. is it possible that something simple like a tweaked thermostat would tell the computer not to turn the radiator fan on?

2. does it sound right that i could overheat a car in those conditions if working normally, but without that radiator fan?(i know in the past i would always here this fan come on when sitting at lights, etc. it overpowers the engine noise)

3. i am going to flush the radiator system for sure, and i was thinking of blindly getting a new thermostat to replace(it has never been done), just to see if it perhaps magically starts working again?

maybe wishfull thinking but i thought it would be a good starting point.

4. i have never had this cars temp gauge go past just a tad over the halway point. during this overheat it did not go any higher either than the typical reading i get when warmed up on a hot day like this.

if it were cold out, it would take 10+ minutes for the reading to be effected from the bottom point and would never reach the halfway mark on the gauge.

also during the overheat both upper and lower radiator hoses were hot as hell. if i idle the car now in the same heat with the hood up both upper and lower are warm. if i warmup the car at night for 10 minutes, the top one gets warm but the lower does not.

also i can turn on the car and turn on the heater full blast and there is warm air when its hot out, which gets hotter as the car warms up. if its cold outside it is cold air until the engine warms up a bit, then it comes out hot.

Sounds like a bad heat sensor not sending a signal when to kick on the fan. Not a real emergency if you are aware of it; just keep an eye on the temp gauge when idling. Shut off if it gets too hot.

Also, you can use the heater to keep the coolant temp down. Turn the heat selector to hot, turn on the heater fan to high or just below (not sure which is most efficient), and that will help keep your temp down a lot. Open the windows if needed to vent out the hot air inside. It'll be uncomfortable if it's hot outside, but it beats screwing up your motor.

[pwgus]

first, the sensor doesnt tell the fan when to kick in on our cars...it tells it when to kick off, so if the sensor is bad, the fan always runs, unless its stuck on the closed position....the only thing I can reccomend would be to try unplugging the temp sensor connector and see if it turns on, if not you have a wiring problem

second, your car will overheat in ANY conditions if the fan isnt working (at least in my experience)

if the fan isnt running, try unplugging it and attempting to splice it in right to the battery terminals to check that its working, if it is I would say you have a fan wiring problem

[TominMO]

your car will overheat in ANY conditions if the fan isnt working (at least in my experience)

If this were true, then the fan would never kick off. But it's not true; if you are going down the road, there is more than enough airflow through the radiator to keep the coolant cool. The fan is not needed if the car is moving at any speed above probably 10 MPH. I have plenty of experience that proves it to me.

[damac]

Ok some more questions after tonights testing and flushing the coolant system

1. Is it possible the jumpering of the radiator fan does not work like that on this model? I cleaned up connections today and found a wiring harness completely disconnected near(not on) the drivers side tail light under the hood. As I went to try and replicate the overheat today, I tried pulling all sorts of connections one by one on the motor. A few made it run bad so I plugged those back in quick The other single blade type connectors I found, like the one in my picture, did not produce any fan when pulled.

As the car warmed up though at idle for 10 minutes, with the gauge hitting the middle, the fan DID COME ON BY ITSELF, and stayed on until I turned it off. It was putting out good flow, just like when jumpered directly to the battery. So either you can't jumper the fan like the earlier models, or I had something unconnected, or its faulty and will give me trouble again in the future.

2. As I let the car warmup the lower radiator hose got hot with the radiator fan spinning. The upper hose was cool, and I also popped the radiator cap off and there was no pressure release and the water was cool to the touch.

3. Before turning off the car I felt all over the radiator and there was no warmth anywhere to the touch after this 10 minutes.

4. I drained the radiator and allowed water from the hose to fill the upper radiator hose. Atleast the first 1/2 came out cold, then it became scalding and hit smoking. I also noticed that with the engine hot and off with me flushing the cold water in, the flow out of the radiator at this point was hot. Does that mean the thermostat is doing its job and letting water through to the radiator?

5. When my car was overheating and the upper radiator hose was just as hot as the whole system, does that mean anything as far as radiator flow and the car trying to pump the fluid through?

I guess while I am screwing with everything I should make sure the radiator and water pump are working ok?

Or maybe the car was ok and I pushed it in the heat and that fan was not hooked up. It was definately hot to the touch at that time, although it did not run out of liquid in those few minutes. That gauge did not really move much though, it was just a hair past halfway, so I am wondering if there is something wrong with the thermostat.

Here is a link to pictures of my 97 aspire, if anybody could possibly point out which wires I should be able to pull to get that fan to go on??

http://smg.photobucket.com/albums/v44/kellyass/aspire/