i recently noticed, that my gauge reads hot sometimes and then drops quickly, first time it did that i checked the coolant, was a little low added water,

and then it does it randomly, coolants level is good. however when i turn the blower on (with temp to hot and AC button on) the needle comes down.


i also noticed the first day, that its leaking from where the bottom radiator hose connects to the engine, above the transmission area.
but yesterday when i was filling up gas, (it wasnt over heating or anything, i just checked) i saw its not leaking from there, but its quit wet under the coolant reservior and it was bubbling.

im guessing its the thermostat, but any input from you guys? how do i diagnose a thermostat, other than taking it out and puting it in a hot pan?

i dont think its the thermostat. i think you have blockage in the system. you need to do a good flush.

I had an issue with intermittent over heating. It turned out the fans were not coming on. Not entirely sure why. After checking the system, apparently a loose wire was no longer loose and it was fine after that.

Well I was just going to post the EXACT same thing mine was doing today! On a st. with the 7A. Im going to flush coolant and replace the thermostat. Im also going check the cooling fans as mentioned and the temp sensor.

would u suggest i replace my thermostat anyways and then just temperarely fill water and take it for a flush? i mean i saw diy videos on youtube but i think it should be professionally done? any input?

its about 100 average where i live

Hey man I just ran to the autoparts store and bought a thermostat for like 6 bucks and some antifreeze. Came home and I removed the two main coolant hoses and the thermostat housing which is two 10mm bolts on the left side of the 7A. The old thermostat looked crappy. I then took my garden hose and flushed water through all lines, the radiator and the block. I also removed the line that runs to my heater core and flushed it til it was clear. Put everything back together. Filled with fresh coolant. ran it till it got warm and that's all the further it would go no overheating! In fact its cooler than it was running and my heater works better now too. It only took about 1 hour at max to do it! Its worth a shot and itll save you money instead of going to a shop!

First thing you have to do is identify and correct any leaks. The coolant system operates under pressure, to prevent the coolant from boiling. If the system is leaking you not only lose coolant, you lose pressure. Without pressure, the coolant can boil, creating bubbles. These bubbles then get trapped, randomly blocking coolant flow.

The thermostat is only testable in a pot of water, though it's simple enough. The leak you mention at the lower hose, if it's between the engine block and the metal sleeve which holds the thermostat, could be due to the thermostat gasket failing. Even if your stock thermostat is still good, you'd want to use a new gasket. I'd agree with Smaay, it doesn't sound like your issue is the thermostat. They either fail to open, causing your temperatures to rise and stay high, or fail to close, causing your temperatures to stay more or less normal except when driving or running the cabin heat.

thank you. it making sense now, its actually leaking from where the hose connects to the housing. ill try to snap a picture next time i see some dripping.

I got a chance to work on if today, when my brother came back from the parts store, I noticed that not only the overflow valve was pouring water out due to boiling water/coolant; but my hoses were sucked flat. Like they were pressed flattish...

Now the cars cool I notice water is low (obviously) so the question is:

should I replace the thermostat gasket and flush the system myself, and if so HOW EXACTLY

UPDATE: I lifter the car to drain the water out, saw that this one hose was open. From my understanding its for the automatic transmission cooling. Correct me if I'm wrong as I couldn't find any other hose that could connect to it. So I thought maybe this Is where it was leaking coolant from. So without plugging it, I added 2 liters of water , nothing leaked. Radiator was fill. I started the car with rad cap off. Bubble came out. Let it reach normal temp. Drove it to get gas. So the car was over hearing again about 3/4 way up. Got home didn't see any leaks other than a lot of smoke and bubbles from the coolant reservoir place.

(Also I see some green stuff on my conpressor, I'm guessing it sprayed out from that hose)















I'm waiting for the car to cool, so I plug that hose thing and add water if necessary and drive it again and see what happens

Any suggestions? Please

need help guys any ideas what i should change/check?
it still heats up even after plugging that hose. water is also still boiling in the reservior

It could be your hoses that are collapsing are weak and need replaced. that would also cause overheating. I think you should still check that thermostat also.

The green oily residue is refrigerant leaking from your a/c compressor. and those lines are a/c lines.

Yea I was thinking I should just replace the thermostat anyways. But the thing is, a few weeks ago my buddy's camry ( 5sfe) did the same thing. We replaced hoses thermostat and the radiator, did the radiator burp thing and he still has the problem from time to time. I worry it won't solve the problem and just waste money.

what's going to make a car heat only when the heater is off. needle stays at half when the heater is on, but as soon as I turn it off, a few seconds later it starts to rise. Then it back in it drops immediately

Replace the thermostat anyways, if it'll help at all, and for $6 you really can't go wrong. It'll be a step in the right direction at the very least

I had this very same problem but mines a 5sfe. I swapped out almost the whole cooling system but still having the problem. I'd recommend you use a infrared thermal scanner thingy. The laser thermal thing. Lol. Sorry don't know the name of the tool. But yea use that to determine how hot the engine block is, upper rad hose, bottom rad hose, and the rad. Make sure they're reading at the right temperature. The reason I said that was because when I had this problem. I took it into a shop and they told me I have a really good cooling system in my car. Looked at them crazy and they said I had a faulty ECT sensor(the dash one). So it was "lying" to my dash that it was overheating when it wasn't. So in other words. Check your electrical components too.

Ok you know your car is overheating due to coolant boiling out of the reservoir. so its not a faulty sensor. The reason it goes cooler when you turn the heat on is because its acting as a mini radiator under your dash. there is something stopping your coolant from flowing through the engine. If your fans are coming on those are good. The things it could be are the radiator is blocked, hoses blocked or weak and collapsing, Bad thermostat not opening to let coolant flow, or water pump not circulating coolant good enough. theres really not much to a cooling system.

Makes sense. The hoses look fine, ill replace the thermostat just cuz. The dealership has a drain and fill for 40$ with pressure test. I guess I'll just replace the thermostat and take it there and see if the pressure if good. If not start from a flush and then rule out a bad waterpump?

yep sounds like a plan.. I hope its an easy fix for ya!

Regarding thermostats and gases:
I had an Olds Cutlass that began to run hot on the highway, with the needle dangerously close to red. I had an extended warranty, and took it to a shop. They replaced the radiator, and flushed the system. I took it out on the highway, and it wasn't long before the temp guage shot right back up. I returned to the shop, and that said that's normal. This car's temp guage was always pegged at the halfway point once it warmed up. After doing some reading, I found that Volvo and some other european car makers were using thermostats with an 3/16-1/8 inch hole along the edge. These cars were having problems with trapped gases, and thermostats don't open for hot gases, only liquids. The hole allows the gases to pass by the thermostat, and have a constant coolant flow. I pulled out my thermostat, drilled the hole, and enjoyed watching the guage pegged at the halway mark.... until my son totalled it in an accident a few months later.

That's why Toyota thermostats are equipped with a jiggle valve, and why they are quite specific about the orientation of the thermostat when installing it.

Have you tried a new radiator cap? If it is broken, your coolant system cant build pressure and tends to start boiling then

Yea first thing I replaced.

replace your thermostat if you havent yet, also your head gasket could be the cause. especially if the your coolant is boiling like that. if you turn on your car with the radiator cap off see if you can smell any hint of exhaust fumes coming through the filler neck.

OR! Try this link. The DIY $30 BLOCK tester method! I'm going to give this a try after I flush my cooling system, change to OEM rad cap, OEM upper hose, and OEM thermostat.

http://www.arrowheadradiator.com/head_gask...n_leak_test.htm

wouldnt pressure testing the cooling system show me the same thing? i mean if the dealer charges 40 for drain/fill and pressure test, isnt that a better option?

Up to you. Lol. I'm more of a DIY guy so I'll learn more about my car and how to work on it. Plus at least I'll know I did it right or wrong.....lol. But it doesn't hurt to take it in for a pressure test.

Makes sense. I barely have time anymore. I'm trying to replace a transmission on a corolla rite now so that's consuming more time. ( Key word:TRYING) haha



Makes sense. I barely have time anymore. I'm trying to replace a transmission on a corolla rite now so that's consuming more time. ( Key word:TRYING) haha

I dropped it off at the dealer for free diagnostics today. Tomorrow ill find out.

Dealer called back said its the head gasket...I'm not sure if I want to believe that. Quoted me 2200$ and 2-3 weeks wait time

2-3 weeks? That's too long. A shop should be able to get it done in 1-2 weeks. Unless they're planning on rebuilding it?

Nah they don't have parts and what not. It's not the time. I really don't think it's the head gasket cuz how would the fans cool the engine down if the gasket it blown? Isn't that some serious thing? And on too of that, shouldn't I see some leaks?

holy crap man. 2200 that robbery! you need to call my buddy Dave at http://www.ddperformanceresearch.com/contact-us.php he is a toyota engineer and has his own shop. he will tell you for sure if its the head gasket and no way will it cost 2200. i can change a head gasket in about 3 hours on a 7A.

Daves shop is in Sealey which isnt far from you at all.

Well if its the gasket I might not keep the 7a

Does he do v6 swaps or 3s? How much would that run me?
I think u told me about him a while back. Is he the one in sealy?

yes to all your answers, he can do the swap, he can do the rebuild. his rates are much better than the dealer. lets put it this way, if i was doing the work, i might be able to do the full V6 swap for 2200. He should be able to do the same

Another shop said its the radiator. Does that sound possible?

If it was the head gasket you'd have oil in the coolant and coolant in the oil and/or you'd have white smoke from the exhaust. $2,200 is asinine, you probably didn't pay much more than that for the car.

Could be the radiator if it is blocked or a majority of the fins are damaged. Have you not replaced the thermostat yet?

No smoke, Toyota said its very small, but its damaged and causing over heating

The shop said the radiator was clogged really bad- they flushed it twice but not good. Asking 500. They offered me warranty and it has about 2500 miles left. If I get the radiator done somewhere else or do it myself its going to void the warrantys

I'm just worried what if I get that fixed and the head gasket was the proble and they don't fix that cuz my radiator caused it to go bad-hence no warranty.

500 wasted, might as well do it myself

You can pick up a good replacement radiator pretty cheap, they aren't hard to replace at all. It wouldn't hurt anything to try it, especially if you still have the original radiator in your car.

yeah I would just replace the radiator, I drove on a leaking one for a while but it was a simple fix beside me getting a defective radiator and forgetting to plug some holes, it woudl've been done in a day.

Well here's the situation,
Option 1. Assuming it is the radiator that's choked, I replace it myself, maybe 120 in parts easy labor I can finish it in about 45-1 hour. Replace all hoses and thermostat.
Two things can happen: I solve the problem. That's good
OR the problem doesn't go away, and I loose the warranty can the shop doesn't replace any other part ie head gasket or waterpump (cause those are the only two things that are left)

Option 2. I pay the shop for the radiator
Either the problem is solved, I wasted 500 on a job I could do,
OR the problem doesn't go away and the shop replaces the waterpump
OR tells me the headgasket is damaged and they won't cover it cuz my negligence damaged it.

I only have 2700ish miles I think left on the warranty. Not sure if paying a shop is worth it, but then that's how much ill be paying approx for waterpump or headgasket(part only) if it doesn't solve the problem.

Kinda confused of what to do.

im confused, what shop has this warranty? whats the warranty for?

When I bought the car, the previous owner had the motor replaced from this shop. That shop gave me warranty on the motor and clutch for 12000 miles, I have about 2500-2700 miles left until the warranty runs out.

Headgasket set isn't that expensive from Rock Auto. Same with the water pump. I say replace the thermostat and water pump since those are cheap, and try to flush out the radiator. Then take it from there.

I have a spare rad for the ST if you are interested.

It was only used for less than a year before the car was wrecked, and it wasn't a front end wreck. So the rad is solid.

Only ran anti-freeze in it, not water. No rust.

50+ shipping...that is 65 less than autozone, and you can swap it out in 30 minutes. Its a cake job.

if you have warranty on it, take it to them and say "fix it!"

Yea I might not get anything replaced from the shop, try the radiator, if not i guess it's swap time. I think it's time I do some major work on my car rather than paying people to to fix things. It worth the experience I guess. Found a camry v6 running for 800 with 1mz. Considering that at the moment.

That's a good price for one.

I like where you are going with this =)

so why doesn't this work? I'm confused. what kind of warranty is it?

They said the radiator is bad, and its not a part that was replaced hence not covered under warranty. Waterpump they will replace if its bad but head gasket I fear they'll say go bad because of me...and not fix it

As of now they say the head gasket looks fine.

I didn't get any smoke or leaks but when I pulled the dip stick after a drive it DID have bubbles on in, I think meaning water mixing with oil and boiling?



They said the radiator is bad, and its not a part that was replaced hence not covered under warranty. Waterpump they will replace if its bad but head gasket I fear they'll say go bad because of me...and not fix it

As of now they say the head gasket looks fine.

I didn't get any smoke or leaks but when I pulled the dip stick after a drive it DID have bubbles on in, I think meaning water mixing with oil and boiling?

I finally got a chance to work on this car yesterday. I took the rad out and then the thermostat. The thermostat isn't sticking when I push it with my had, but looks like its stuck open a little bit and when I put it in boiling water it didn't really open more
Not movement.

So I'm guessing that's my problem. Since I have the radiotor out anyways I'm gonna install a new one too.
Autozone and oriellys have the same part number for the thermostat for the GT and ST celica. The one that came out of the car doesn't look the same, it looks bigger or wider from the bottom.


Any idea of of it thes same thermostat or should I got with dealer?