:( can anyone help me here. first of all I try the various tests to tell if its the thermostat or the water pump and still dont seem to come up with anything certian to steer me in one area or other.
can anyone tell me a definitive way to tell if you need first of all a thermostat as i hope thatt is all it is. (the car doesnt leak water from anywhere)when i watch as the car idles after warming up i dont see the fluid passing by looking down in the radiator with cap off. the upper radiator hose is definitely hot after warming. ( i was told after warming up, it could remain cool if thermo isnt opening up) there is a brand new radiator in the vehicle or 3 months old anyway.when i turn on the air conditioner it gets dangerously hot very quickly. however when driving 60 or so down freeway, it keeps the temp from just blazing over. however when i get off in traffic it starts its climb to HOT very quickly. any suggestions, should i go ahead and gamble on thermostat anyway as it could probably use one anyway?? help???? thanks girard

I've never taken a waterpump on this 92 toyota off or taken one apart, and I am curious, what turns a water pump of this sort?? I'm not even exactly sure where it is on this vehicle. I'm used to the ones on old 283 chevy v 8 engines or cars where it is up front staring at you almost.
I was just curious, does this type of water pump turn by belt or it is electrically driven???? thanks, girardo

when i watch as the car idles after warming up i don't see the fluid passing by looking down in the radiator with cap off. the upper radiator hose is definitely hot after warming.The hose should not be hot. Sounds like the thermostat isn't opening up.
I can tell you the water pump is powered or turned by a belt.
Also I have changed out a water pump on a 88 corolla 4 cylinder and the motor is in side ways. Thus you have to unbolt the motor mount & jack up the engine.

yes ive found it on the opposite side of the distributor cap at last. yesterday i drove it a bit too long and the upper hose got so hot it blew a slit in the side. I suspect the water IS being driven by the water pump and the thermostat is closed and the water cannot circulate. the thermostat is in a bit of a tricky spot but i do think i can get it out. do you agree it is most likely the thermostat? thanks girard

Yes, that would be my guess!

ive got me a new thermostat, and i notice that my toyota manual stresses the point on where to position the 'air bleed hole', its a hole maybe 1\8" diamiter in the thin metal rim near the edge of thermostat. the thermostat i bought doesnt have one. I'm curious, is it critical to have a thermostat with this hole in it, or will 'burping the engine" when i first install it(running it with radiator cap off for about 30 minutes to be rid of all air) be sufficient? thanks girard

Does the engine/radiator cooling fan come on at about 226 degrees f ???

well since this last post ive been driving the car with the thermo that doesnt have a bleed hole in it, and there are no overheating problems. i would like to share the fact that many of the 'field tests' that can be performed had misleading info in some ways. for example 'if the thermostat isnt opening the upper radiator hose should be cool cause the water isnt circulating'. that turned out to be untrue, my thermo wasnt opening therefore the water was being pumped by the water pump and pressure and heat were rising in the upper radiator hose, with the water having nowhere to go. I went with instinct and it did turn out to be thermostat. (never discount instinct perhaps) I got this info from a hayes manual too. Also it said, 'with the engine at normal operating temp, you can squeeze the upper radiator hose and let it go, and you should feel a surge of water circulating if the water pump is operating properly'. when you squeezed mine it was hard as a rock as to the water being driven up in the upper radiator hose with nowhere to go, so you really couldnt squeeze it properly, and the water pump was working fine.

Thanks for input!!!

ive got me a new thermostat, and i notice that my toyota manual stresses the point on where to position the 'air bleed hole', its a hole maybe 1\8" diamiter in the thin metal rim near the edge of thermostat. the thermostat i bought doesnt have one. I'm curious, is it critical to have a thermostat with this hole in it, or will 'burping the engine" when i first install it(running it with radiator cap off for about 30 minutes to be rid of all air) be sufficient? thanks girard

I'm Curiouse about this bleed hole in the Toyota Thermostat. I have a friend who says he has to change the Thermostat to one without the hole in order for the car to SHIFT INTO OVERDRIVE ON WINTER DAYS. And, changes back to the THERMOSTAT WITH THE HOLE in the summer to avoid overheating. WHERE SHOULD, THE POSITION OF BLEED HOLE, BE PLACED WHEN INSTALLING THE HOLE THERMOSTAT? The car is a 93 Paseo.

Bleed hole UP is the usual position.