View Full Version : My 95 GT overheating problem

02-13-2011, 11:24 PM
I have a 95 GT that overheats after awhile and then cools down once I start giving it some gas. One of the hoses recently ripped while I was coming back from a camping trip and my car overheated, but I keep turning it off before it hit the red and just kept adding water until I was within my towing mileage limit and then the car turned off. I replaced the radiator hoses, but the car still overheats. I checked for water in the oil and checked to see that the fans were working properly. I figure it must be a sensor or something, but since I'm no expert I would like to know what you guys think before I do anything else.

02-14-2011, 05:37 AM
Do you have just straight water in your radiator? You should have a 50/50 mix of distilled water and Toyota red coolant.

02-14-2011, 10:14 PM
Yeah. I had coolant and water but it leaked out. I'm planning on adding more coolant but I don't know if it will help because it seems that the fans aren't going off when the car starts heating up. Maybe it's a fuse or relay? Don't know which one is the relay for the fan either.

02-15-2011, 12:42 AM
Well I would definitely say you should get some coolant in there and not just water. If your fans aren't turning on, you may want to replace your thermostat. Sounds like the thermostat may not be working.

02-15-2011, 02:02 AM
Your cooling system is a 'sealed' and pressurized system, if it leaks, you have an issue. Pressure test it, repair or replace the problem, then refill with 50/50 like my man Walker explained earlier. It's probably a good idea to change the theromostat while doing this.

To properly fill(preventing air being trapped) the system after repairing the leak, and installing the thermostat:
Fill while running the engine, have the heater on the hottest setting and the fan switched to the highest setting. Once the rad fill's you can place the rad cap on with only one click, dont close it fully to two clicks(this just prevents splashing, but the radiator can still let air and steam out of the neck past the cap). You'll have to wait a bit to let the thermostat open.(your fan should turn on when it does this) your top heater hose will get very hot, this is the hot water from the engine that the water pump has been trying to send to the radiator to get cooled. Your thermostat prevents this(good reason to change this inexpensive part when working on the cooling system) when the engine is cold, it diverts the water and it still circulates, but not to the radiator for cooling. When the engine gets hot enough, the thermostat is suppose to open and let that hot water flow to the rad for cooling. If the thermostat, fan, sensors, fluid, or water pump is not doing its job the engine will overheat.

see the BGB link here for more info:

02-15-2011, 04:26 AM
in an emergency there is nothing wrong with running straight water. thats what i run in my 7th gen race car. its not going to hurt anything to get you home

02-15-2011, 05:14 AM
It's force of habbit bro, our climate up here has us trained never to forget coolant/antifreeze hehe :)

02-15-2011, 08:28 AM
Simpler question: after you replaced the ripped hose, did you properly bleed the system to get the air out?

As I recall, there's a temperature sensor on the radiator which determines when the fans spin up -- if air is preventing water from circulating into the radiator, that sensor is never tripped.

02-15-2011, 09:43 AM
Ok well is your fan working at all? When you let it heat up have you seen or heard it kick on to cool the radiator? Will the heater on full blast help keep the temp down? Will turning the A/C on help keep the engine temp down?

02-15-2011, 06:16 PM
So as long as you're moving at a decent speed [say above 35 mph] it doesn't overheat?
And once you slow down/stop it does?
And your fans aren't turning on?

If so it's probably your fan switch on the passenger side bottom of your radiator. There's a 2 wire connector there, unplug it. If your fans run that switch is most likely bad.

02-15-2011, 08:33 PM
The thermostat is practically new. It was installed a month ago, as for the fans yes they do turn on just not when the car is over heating and the heater does help with the temp but not as much as it should. The a/c helps also but it takes longer for the temps to go down when I turn it on. I'll check the car today and bleed the system. Gonna put coolant in and see if it was just air or if my relays or fan switch need to get replaced. Thanks for the replies!

02-15-2011, 09:04 PM
If your fans turn on the switch should be fine. I wasn't sure if the fans were turning on at all.
That sounds more like a thermostat or blown head gasket.
Usually with the 5S even if you have an air pocket it gets out pretty quick, the system doesn't tend to keep them.

02-16-2011, 12:08 AM
I hope it's not the head gasket. I just found coolant leaking, but I don't know from where. It's near the lower radiator hose. I'm thinking the water pump is on the left side of the engine, so where could the leak be coming from?

02-17-2011, 05:38 PM
Could be the water pump. Lower hose runs into the therm housing which attaches to the water pump.

02-17-2011, 08:43 PM
The thermostat is on the left side. It's a small hose that is under the top radiator hose. I'll take a picture because I'm getting confused since my thermostat is on the left, but I've seen diagrams saying it's on the right.

02-17-2011, 09:00 PM
If you have a GT [5SFE] the thermostat [and water pump] is on the R side. Directions go by sitting in the drivers seat.
Pics would help.

02-18-2011, 12:35 AM
Oh, ok, sorry I was going by standing in front of the car so the drivers side would be my right side. My mechanic checked the car and couldn't find any reason as to why it would leak or over heat. He said he didn't think the head gasket needed to be replaced. There is rust in my radiator, what can I do to get rid of it? How do you get the pictures to appear without the links?


02-18-2011, 01:43 AM
Another thing to look at is the condition of your radiator. I know when I had problems like this, I was having to use my heater just to keep from over heating at stop lights. When I looked at the core of the radiator through the radiator cap it had large amounts of mineral deposits blocking the openings of the capillaries or tubes. So much that I knew that was my problem. So I replaced the radiator and had no problems after that.

02-18-2011, 04:25 AM
I'll look into that, thanks for the suggestion/advice!

02-18-2011, 05:20 AM
yeah, thermostat is there

04-07-2011, 09:24 PM
Got the heads checked and new head gasket installed. Apparently the gasket had a few holes but they weren't big enough for enough water to mix with the oil, so for awhile it didn't seem like it was the head gasket. Now I have an acceleration problem :(! It started a little after my car started heating up. The mechanic thinks it's this thing that a hose connects to, he says that it regulates air, but I'm not sure what the part is called and if that's what it is. My rpms were fine for a bit after he changed the gasket but then they dropped to about 300 and the car felt like it was going to turn off. Any idea why that is? Thanks for taking the time to respond.

04-07-2011, 10:01 PM
Has your mechanic set the ignition timing correctly or has it slipped?

04-08-2011, 02:27 AM
"This thing that a hose connects to" is insufficient detail. Pictures are much more help, or a clear specific description.

04-08-2011, 04:23 AM
Maybe talking about the temp sensor for the ECU?

04-08-2011, 06:32 AM
I'm not really sure on any of those things, but I will take pictures and upload them. I didn't know the name of the part, but I looked it up and I'm thinking it is the egr valve. I found other things that could possibly be the culprit, such as the acis actuator. When I start the car it takes a bit for it to get up to close to 1rpm and then the minute the car idles the rpm goes down to between 800 and 500 rpm. When driving it goes down to about 300 and the car feels like it is struggling to stay on. Thanks for the replies. Sorry for the insufficient detail.

04-08-2011, 07:30 AM
Engine coolant temperature sensor is wired, but doesn't connect to a tube (well, it sort of screws into one).

04-12-2011, 08:37 AM
How many quarts of transmission fluid for my 95 gt with a 2.2 engine? Also I cleaned the throttle and the rpms went up a bit, but my car still shakes and idles rough. Any ideas on how to fix that? Thanks for the input/help!