my driveway is on a slight slant and i just ran it again with the cap off for about 10-15mins. took it for a test drive about 30mins in rush hour traffic no problems........ i think it was my thermostat. old one opens up at real slowly at boiling point on the stove.....

 

This morning i was on jzs147.com and they had a diy on the thermostat. i din't read it before installing the new one..... how important is it to line up the thermostat (metal ball on top) to the housing.... the car runs fine now but it says it is very important to release bubbles????? will i be ok or should i change it now before i run into issues. im not even sure my new one had the line up mark on it.

 

They have failsafe thermostats that if they fail they fail in the open position.

You need to let the bubbles out to release air trapped in the system. Having the engine on an angle helps the air go up and out.

The metal ball(jiggle valve) must be installed within 30 degrees of either side of the proper position which on a 430 is top dead center.

 

the stant thermostat i got from advanced doesn't have the metal jiggle valve. but i got all of the air of the system.

 

I dont know if it has been said yet, the toyota water pumps have a seepage hole that coolant/water comes out of when the water pump internals are starting to go, or are messed up.


Oh and with the thermostat, it is best to rotate it so that the small hole (with a piece of metal in it) is located at the 12 o'clock position.

What this does is allows any air bubbles trapped in the system that ride along the top of the coolant passages to pass through this little air hole and make its way to the radiator much easier where you can top off the system.


also, side note if you areover heating and there are no blocked passages in your radiator and no signs of leaks, check out your fan clutch. over time they dont really lock up as well, which really hinders your fan from spinning with its maximum torque. Hence it does not pull air through the radiator as well which leads to overheating and higher coolant temps. New ones can be had from www.rockauto.com for 50$ vs. probably 300$ from the dealer.
and if you can try and stick with dealer thermostats vs the simple auto store replacements.

you can also find direct OEM replacement radiators(ChiCom..[china]) for 40$-60$ + s/h and they work very well.
After all, factory radiators were only single core as well with plastic tops and bottom.

 

Replacing the thermostat was the very first thing I did. Then I noticed my resevoir was bubbling. Do I have air in the system?

 

mccalj: If the resevoir is bubbling, do I have air in my system. I replaced the radiator cap and thermostat. When I take the cap off, when cold, coolant starts to come up and out of the radiator slowly. It seems like its still under pressure when cold.

 

mccalj: I must have air in the system. I replaced the thermostat, but putting it in the correct position is questionable now. I also replace the radiator cap. The resevoir doesn't bubble up, but it still leaks from the. Not as much as before. I took my radiator cap off, when cold, and the coolant started coming up and out of the radiator like still under pressur. When air is still in the system, would that cause the coolant to push out? Thanks for you help.

 

mccalj: So, while the car is running on an angle, do I leave the radiator cap on or take it off? I've been told both. And for how long? Thanks.

 

One of the replies that I got was to position the small hole of the thermostat to the 12:00 position, which allows the air to release from the system . I'm not sure if I did that, but am going to redue my thermostat to make sure it is in the right position.

 

I'll take a quick note and double check to make sure I put the thermostat in the correct postion. Thanks for your help.

 

I changed my thermostat as well. Make sure it's in the 12:00 position with the little hole on top. I was told that it allows any air bubbles to escape. Good luck

 

I recommend checking to see if you head gasket is blown. If it is, then my suggestion is that(head gasket) should be the first priority.

-To test the head gasket you can try this:
With the engine cold(NOT hot, NOT even warm...COLD ONLY[for liability purposes]) take off the radiator cap and make sure the the coolant/water level is good and keep the cap off.
-Now start the car, and walk back over to the the engine bay(on the side away from the radiator's coolant inlet hole).
-Now pull the throttle cable to give the motor a few quick, hard revs and watch the radiator's coolant inlet spout.
-If the coolant/water is bubbling & pouring, or gushing out(mine shot 3 inches out of the spout) then there is a very likely chance that you have a bad head gasket, or worse(not likely) a cracked block or head.



-If it bubbled, then pull on the throttle cable again but this time you don't need to "hard revs", just give a nice slow gradual pull to mimic you stepping on the pedal and holding it(try to keep the rpm around 2,000rpm). Do this for 10 -20 seconds while watching the radiator's inlet hole.(it helps to keep having someone top it off while this is going on)
NOTE: If your friend helps you top if off, and the water comes out just as fast as it goes in, you head gasket is blown(In my opinion).
-What you are trying to do is verify that hopefully it is just air bubbles in the system(20 sec. is more than enough), and not the exhaust gas from the cylinder entering through a blown head gasket into the coolant system, or even worse a cracked head.







Also as I stated in my previous post above, did you check your fan clutch? You can have a new radiator, new thermostat, new hoses, and new cap, and still over heat and bubble because the fan clutch is not working.

its 50$ at www.rockauto.com

I just replaced mine and because I bought the car with faulty fan clutch(and did not realize it) I spent 1,000$ in parts and labor over the last 1.5 years(2 radiators, thermostats and radiator caps(thinking these were always the problem), and finally a headgasket kit (due to the previous owners negligence) all because of this 50$ part.

If you haven't checked it, you might want to.





And if you do end up changing the head gasket(head gasket kit @ rockauto is $100 + 50$ for new head bolts), I'd recommend(if they haven't already) changing the timing belt[13$-rockauto.com], water pump[51$], spark plugs(iridiums)[36$ for 6], and the power steering pump's gear and seal(13$ kit[rockauto] vs 199$ for a steering pump). Or if you really like you can change the whole power steering pump. You may as well do all of this because all of these parts will either be taken off or the mechanic will have very easy access to so you wan't have to pay for labor on these. don't forget the serpentine belt.

If you were in calif. I could point you to a mechanic that did my head gasket kit for 600$, lexus wanted over $3,000 and 500$ for 1- head gasket, and 14 head bolts.



Didn't mean to ramble on, but I'm just trying to help from my past experiences



Also if you change the radiator, stick with the ones made for the gs300. I have tried the made in china(1 row.) ones for 40$ and they work well provided that your fan clutch is not malfunctioning. Otherwise they act the same as stock and overheat. Stock radiator by the way is 1 row as well just for your info.


The supra All aluminum 2 and 3 row radiators look like they will work but require some modification. send me a PM if you want to go this route. I have an all alum 3 row sitting in my garage that I plan to try and re-install soon.

 

Kene thanks for the input..... i think i fixed my problem. it was a faulty thermostat. my fan clutch works fine i checked that. but i did notice that my two radiator electric fans are not working. one doesn't spin at all and the other turns at a super slow creep. when i ride with no ac on the car stay just under the half way point on the temp..... but when i cut the ac on it starts to climb and gets close to the H mark. as soon as i turn the ac off it goes right back down instantly. Will the fans not blwoing cause this???? and can someone lead me in the right direction wiring the fans????

 

Now are these aftermarket elec. radiator fans that you added, or is it the one on the drivers side section of the radiator?

I'm not doubting you, but a faulty fan clutch will still spin freely even though it is bad. It just will not lock up and force heavy amounts of air through the radiator.

also I think this is interesting in the fact that:


1-your car is running.
2-if you run the A/C[engine works harder due to A/C compressor taking a little power] the temps rise to the Red Hot mark(possibly electric fans not working?)
3-As the engine bay starts to get hotter, the metal coil on the fan clutch(exposed to atmosphere) should see this heat and lock the fan's clutch in place, so now the power of the motor is fully spinning that mechanical radiator fan.
4- 3,200 cfm worth of air is now forced through the radiator(not to mention road wind) and your temps should drop to their normal place.

Note: I'm not sure if you have aftermarket fans too, but most of the aftermarket elec. fans pull a measly 1,200-1,400 cfm(there are exceptions like Zirgo fans) vs stock 3,200 cfm....if you do they are only getting in the way of the stock fan preventing itfrom doing its job.



This is why I wonder the condition of your fan clutch.
Many times over the years dirt and debris build up in between the spaces of the temp. coil spring that is on the outside of the fan clutch. I believe this can have an adverse affect on its engagement.



Check these links out:

http://www.toyota-supra.info/forums/...rbo-supra.html

http://www.dragtimes.com/parts/TOYOT...757590644.html




Look 19 images down, is this the electric fan you are talking about?
http://www.toyotalexusforum.com/clas...c-kendall.html







.