Coolant keeps getting too hot!! Help!! - Toyota Nation Forum : Toyota Car and Truck Forums

89_3SFE · 07-28-2005, 08:35 PM

I just today had my thermostat replaced because my 89 GT was getting too hot. The mechanic replaced it and he ran the car for a pretty long time and it didn't budge, so they figured it was fixed. He told me to just watch it and when I drove back home after about 10 minutes, it started increasing in temperature. It slowly increased but it never really overheated. He
told me to replace the radiator cap and see if that fixes it, but I don't know exactly what's wrong with it. I know it's either a clog in the radiator or somewhere in the pipes that's keeping it from flowing as fast as it should. I guess it could also be the pressure on the cap. I wonder if maybe a cooling system flush would help. Can anyone help me out??

Tommy · 07-28-2005, 08:53 PM

you can try to flush it, some where on here there is a write up on how to completly flush it. That might do it, if its clogged.

***MRQtwinturbo*** · 07-29-2005, 10:27 AM

how old is your rad??....

89_3SFE · 07-29-2005, 10:30 AM

I'm guessing it's pretty old. I've had the car for 2 to 3 years and I've never replaced it, and I don't think the original owner has replaced it yet. If it is the radiator, wouldn't it just leak, and if was clogged, can't I just get a body shop to unclog it for me?

Tommy · 07-29-2005, 04:52 PM

chances are if the radiator is clogged, you arent going to be able to unclog it. New radiators are about $100, so it might be about time.

89_3SFE · 07-30-2005, 05:16 PM

I'm going to keep you posted on how it's going, so here's some more info that I found out today.

I got the thermostat replaced, and the cap replaced and I also got the whole system flushed. I thought I was good to go until I had been on the freeway for about 10 minutes. I had the air conditioning on the whole time, mind you. It started to very gradually get hot, so I flipped the A/C off and turn it to heat, but it didn't change it much at all. I decided to keep the A/C on because sometimes I noticed that the temperature gauge would slowly move back.

It just seems like the temperature gauge is so spastic, but I think it's giving me a correct reading. When I first start the car, the temperature gauge is cold and it starts to creep up as I drive more. It then stays at a good position for a little while, and then that's when I've been having these problems. How can I tell if the temperature gauge is shot? What if something is screwing up the reading and the coolant is really pretty cool? When I turn the car off, but turn the key to ON, the fan blows and the temperature gauge is pretty low, but then I'll turn the car on and it shoots up past what it should rest at.

I'm lost on this one. The only thing I haven't replaced is the radiator, and I thought those only went bad if it leaks, and it ain't leaking anywhere. I don't really know what to do. If anyone could help me, please do so 'cause I'm in desperate need of help!! Thank you guys!!