'87 22re Thermostat refuses to open.
 

Guys i'm stumped. i posted this truck for sale about a month ago now, because i was feeling really good about it. it was running and driving great. as soon as i started getting interest, it started having over heating issues. ( a little more gradually than that but it was still pretty sudden) I've put in 3 brand new thermostats from 3 different stores, also, a used thermostat from a running vehicle that never overheats! I replaced the water pump, fan clutch, radiator, radiator cap... i dont know what is left.
The truck starts up great every time. runs for 5-10 mins and the temperature starts climbing pretty quick after that. Heat blows hot. Both upper and lower radiator hoses stay cold. with no thermostat, and just the gasket in the housing the truck can run and drive all day and not even come up to temperature.

Any input, suggestions, constructive criticism would be very much appreciated. thanks in advance!

Flushed the cooling system? The coolant passages may be clogged from years of neglect.
Tested the thermostats?
The thermostat you took from the other vehicle may be set to open at higher temp?
try this store for OEM? Toyotapartsdeal.com

never flushed the coolant system.. i figgured with a new radiator, and the heater blowing hot, that wouldnt be an issue still worth trying i suppose. The thermostat out of a running vehicle that never overheats was another 22re. I dont see any reason why one 22re would be meant to run hotter than the other?

testing the tstat is pretty easy to do - simply stick it in boiling water and it should open/move.
burped the system clear of air pockets?

The radiator is not the only thing that gets cligged. Coolant passages in engine do, too. I flush my cooling system every 2 years.

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Air is a very poor conductor, an air pocket under the valve will stop it from opening.

There is also a case for making sure you put it in the right way around..

And finally how accurate is the temp guage and how do you know this.

i think i'm going to try a coolant flush. i've seen additives for coolant flushes, any reccomendations?

Bow do you "burp the system" ? when filling coolant i usually leave the radiator cap off untill the engine begins to warm up, but the thermostat never opens, so therefore no air comes out i'm guessing.

i have no way of telling the true accuracy of the temperature gauge, but when the gauge says it's hot, it's hot. just put your hand on the valve cover and it says it all.

try drilling an 1/8 inch hole in the thermostat (on the plate next to the valve) that will insure that you don't have a vapor lock. or try it without a t-stat to prove it's not something else.

they have ran it without a thermostat, it never got warm. This leans towards airlock. A weep valve (hole) will help here.

+1 on drilling hole on t-stat.

I use the Prestone Flush and Fill kit to facilitate back-flushing the system: https://www.walmart.com/ip/Prestone-...3=2479&veh=sem

After back-flushing and draining the system, I refill with Prestone Flush/ Cleaner Additive and DO THE HEAVY-DUTY FLUSH DESCRIBED ON THE BOTTLE. : https://www.walmart.com/ip/Prestone-...3=2479&veh=sem

https://lh3.googleusercontent.com/f3...=w1289-h725-no

A tee fitting in the heater line is also a good way to vent air when filling the system, or crack loose the hose from the valve, as these are high on the firewall.

Yep, That's what the Prestone Fill n Flush Includes.

https://www.walmart.com/ip/Prestone-...3=2479&veh=sem

Thanks everyone for the info! i'm gonna pick up a bottle of prestone after work today, and give it a shot. i'll also try either removing the tstat again, or drilling a hole in it (which i've not yet tried) before the flush if you suggest that. Also great point on the Tee ontop of the heater core hose. i'll try that too. think it matters if i do the hose going in or coming out? or just whichever one sits a bit higher than the other?

Thanks again everybody, i'll let you know how it goes at the end of the day!

Not sure but my truck came with the Tee on the "A" hose so I put it back there.


If you have an assistant, you have a choice to not use a Tee; just disconnect hose from one side of heater and flush from there, then the do the other
hose and flush from there. That's what I did with my daughter's Corolla.

Best to do the rinse with thermostat out. The key is while RINSING, squeeze various hoses (heater, radiator IN, Radiator out, heater in, heater out) so water runs back and forward through radiator and heater coils. I make sure that water runs from bottom radiator hose to exit at cap (back-flush).


Yes please. When you first drain from a few hours of "Heavy-flush" I'm curious to see what comes out. This came out of my daughter's 2007 Corolla. (Yours will probably be browner :) )
https://lh3.googleusercontent.com/FT...W=w564-h751-no


https://lh3.googleusercontent.com/Nj...s=w423-h751-no

Aside from paying attention to not installing it upside down, did you pay attention to the location of the "jiggler valve" on the tstat?

I did the tstat on my Land Cruiser last month and it required the jiggler valve to be positioned within a specific 20* range in the housing for proper install. Way I understand things is that if you do not install it correctly, the air behind the thermostat can't pass through to burp the air from the cooling system.

i feel pretty confident i put it in right. with the copper cylinder with the spring around it on the bottom. i dont know about a jiggler valve, as far as i can see it's pretty straight forward with no adjustments available.

Rad4runner i've got it running now with the prestone. i'll give it another hour and a half or so, then i was thinking i would let it cool, drain it, and see what it looks like. then maybe swap the heater core hoses and try again?

The "jiggler" valve on the thermostat should allow the air to escape from one side of the thermostat to the other, even with the thermostat closed.

If you are using a high quality thermostat, there should be a "jiggler" valve in it and there should be no need to drill a hole through the thermostat.

If you did not install the thermostat upside-down, you installed it correctly. It faces up so there is no "adjustment".

:safari:

truck has been running for about 2-2 1/2 hours now, with prestone and no thermostat. smart thinking running it without the thermostat. water/prestone mix is circulating nicely, and beginning to look brown and murky.

:) Drive it for a couple of days like that, UNLESS YOU HAVE FREEZING TEMPS, then drain and rinse thoroughly before refilling and burping.
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I drove the truck yesterday morning from 8-2:00 had it running the whole time. definetly a good call doing the coolant flush, but i dont believe it was the solution to the problem. Drained the radiator, and refilled with another coolant flush. this time i tried Blue devil, because a local guy said he liked it better. i Let the truck run for a few hours lastnight over dinner and shut it off before bed. woke up this morning to check the radiator and all the liquid was pretty clean so i figgured hey lets put the thermostat back in and see what happens. Nothing different. i let the truck warm up for a couple minutes then went to drive it. by the time i halfway down the driveway it was climbing pretty quick.

I've been given lots of mixed reviews on this subject. half the people i talk to say it's a head gasket. the other half say there's no way because you cant smell coolant in the exhaust, you cant smell exhaust in the coolant, the oil stays clean, and it wont overheat with the thermostat removed. Aside from a slight miss at idle, the truck runs really good. starts every time, and has no problem with power issues.

hopefully everyone is still following this thread because i'd really like to hear what you have to say.
Thanks in advance,
Ray.