help, temp raising

[arizzle]

ok well i tryed searching but nothing seems to be coming up. well i did a Hg job about 10xxxk ago, and i did a new water pump, all new gaskets thermostat, are all new. the pass few days my cars temp has been going up when im idling and almost reaches the red, but once i start to move the temp slowly goes down and the faster and higher i rev it seems to get colder then usual. i dont know whats wrong its only when im moving the temp stays slow but at a stop it raises! could it be my clutch fan? or could any of the things i replaced fualty ?

 

[CyFi6]

Perfect symptoms of a bad fan clutch. Is your fan shroud in place? Try spinning the fan by hand with the engine off when its cold, it shouldn't do more than probably a turn if that. It could be other things as well though, such as blockage in front of the radiator.

 

[Who]

and almost reaches the red,

Stop taking it to red... The temp guage is a liar! Anything above the 1/2 mark is hot enough.

 

[gtsfirefighter]

Perfect symptoms of a bad fan clutch. Is your fan shroud in place? Try spinning the fan by hand with the engine off when its cold, it shouldn't do more than probably a turn if that. It could be other things as well though, such as blockage in front of the radiator.

I agree. Check the fan clutch. Blockage inside the radiator could be an issue as well.

 

[arizzle]

Stop taking it to red... The temp guage is a liar! Anything above the 1/2 mark is hot enough.

Well if im at light am i suppose to jus turn it off? Lol

But yes ill check those today before i go to a local toyota meet

 

[Muzy]

Well if im at light am i suppose to jus turn it off? Lol

But yes ill check those today before i go to a local toyota meet

I think he would mean, stop driving and find the root of the prob. As you
may be doing damage. Factory gauge would be a guide. Anything remotly
close to red is bad news. Gauge might be readding low, but why gamble.muzy

 

[johnathan1]

Sounds like your fan clutch could be bad...when the gauge reads hot, and you rev the engine is the fan very loud? It should be.

To test it, the engine has to be HOT, not cold like someone else said...turn off the engine while it is hot and try to spin the fan by hand. If it turn more than about 2 revs, it needs to be replaced...

Also check your radiator for cold spots...there are a ton of small passageways in the radiator that can become clogged with junk (sediment, rust, etc) and will reduce cooling capacity.

Do you have to add coolant often?

 

[arizzle]

Sounds like your fan clutch could be bad...when the gauge reads hot, and you rev the engine is the fan very loud? It should be.

To test it, the engine has to be HOT, not cold like someone else said...turn off the engine while it is hot and try to spin the fan by hand. If it turn more than about 2 revs, it needs to be replaced...

Also check your radiator for cold spots...there are a ton of small passageways in the radiator that can become clogged with junk (sediment, rust, etc) and will reduce cooling capacity.

Do you have to add coolant often?

Ya my fans do go one once im in proper operating temp, and as for the fan clutch i still havent checked it when its hot, only when its cold and it doent seem to be moving easily. Im planning on doing a coolent flush hopefully tom,

And as for adding coolent i havent added any since the bhg, and it was full this morning.

 

[p5150]

every time I have seen a fan clutch failure it has locked up solid. Sounded like my car was fast or something...

 

[arizzle]

ok well i check my fan clutch once it was warm but it still good, but yesterday i did a complete tune-up and it was fine all day except for the one i was in a drive thru and it slowly went up but then it went down, i took it to my mech and he said the thermostat my be getting lazy to open, so im ordering a OE stat and to see if it will still happen, but car heat hasnt gone up besides that one time.

 

[johnathan1]

Try replacing the thermostat and get back to us...

 

[Boosted7M]

Thats what i was going to say that it might be a thermostat problem. but like ^ said do that and see where it goes.

 

[shaeff]

Also check for pinholes in any coolant hoses. Even a tiny pinhole will cause temp spike problems. You drive, the system is pressurized, it leaks the coolant out, you shut off the car, air seeps in and creates air pockets. Once your car is up to operating temp, the air pockets help the car to run hotter, thus potentially boiling the coolant, spiking the gauge, etc...

 

[Who]

^ Pressure test your cooling system.

If you do replace your thermostat be careful not over tighten the bolts.

 

[shaeff]

Often times a pressure test won't yield good results. I did a pressure test on my Supra's cooling system, and it held pressure just fine, but I definitely had a leak, which I eventually found.

 

[johnathan1]

At 21psi or so, most leaks become very evident lol.

 

[shaeff]

I thought so, too. I had that thing pressurized to 20psi and still didn't find it. I squeezed all the hoses all over the motor, no leaks anywhere! It was incredibly frustrating. Then on my way home from work one day, my upper radiator hose literally blew in half. There wasn't a hint of a hole on it when I checked.

Replaced that hose, all my cooling problems went away!

 

[arizzle]

well i did a pressure test and it held the 20psi just fine, but im going to be replacing the thermostat once i get a chance to its just been pretty cold and im parking the supra on sunday. but it seems to be good for the pass couple days, the first time i had to add water it the overflow was sat.

 

[arizzle]

ok guys well i replaced the fan clutch and a new thermstate and it was fine the day i installed everything, but now the temp jumped just under the red an i couldnt pull over right away when i stopped the temp just dropped to normal and stayed there, im thinking the thermostate froze or just got stuck.

the night i installed it it was 2celious and then the next morning it was -18!!!! so i dont know. help guys

 

[Muzy]

Have not seen it my self, but cars as old as these could have the impeller part of water
pump corrode enough that they become useless. I'm used to bearing or seal going south
first. muzy