calderondean

Im working on a 1993 Pick Up with a 22RE engine. I odered the dual stage thermostat today (90916-03070) but not really sure if that will fix the problem. The truck has a new radiator new water pump new belts and hoses and the engine has been recently rebuilt, but for some reason it tends to run hot and it will loose some coolant everytime I check the radiator,but their is no leaks anywhere I look, has anyone had this problem before please HELP !

korn111685

do you do alot of stop and go? when your moving your fan does'nt do alot of work.. but when you going less the 15mph or so.. it pulls air.. check the fan clutch..

to check the fan clutch start the engine (cold) let it idle then turn it off, watch the fan or have a friend watch it. if it spins for more the a second then replace it.

i had this problem not long ago. along with a newer rad mine runs cool.. matter a fact.. i'll need a hotter t-stat during the winter b/c the hand only shows it runing 1/4 temp.

no water in oil right?? you can check that that'll be due to a back timing cover or hg. but you said it's rebuilt.....???

sniff the coolent.. if it smells like exhaust.. bad hg

just have to look around.. took me a while to figure out my deal.

calderondean

Tnx for the reply ! yup I checked the fan clutch its working good coolant smells fine cause I can smell it real good when it boils over to the resevior. I put in a new t-stat in it a few days ago but its not the dual stage one it ran well for more than half the day I even had the A/C blasting nonstop till the end of the day until the temp started to creep up on me, then that night I checked the coolant in the radiator and I saw that it was low but not that low I only had to add a little bit to fill it right up. I tried to run the engine again in my backyard that same night to see if it would start to get to hot and it did after about 20 to 30 mins.and when I checked the radiator it was a little low again, but I tried this test before when I put T-Stat in and I even ran it longer and it was fine and like I said I used it the following day for work and even filled the bed up with a heavy load and ran the A/C all day like I said and it was fine till the end of the day, so now im going to try out the dual stage t-stat and hope that works, hope its not the H/G like you mentioned if you have any other ideas pls let me know I really will appriciate all the help I can get !

calderondean

Ill smell the coolant again just to make sure !

korn111685

well not everytime you lose water does it mean something bad is wrong with it. heck i was loseing water when trying to cure my cooling blues.. ran the engine to the red line a few times during the time i was trying everything i could to cure it.

like i said i lost water.. but after changeing the rad and fan clutch... i am golden. the old rad held pressure so it was good.. as far as being sealed. but it was clogged bad.

like you said give the t-stat a try. with a new rad, pump, fan clutch, and a rebuilt engine... should cool just fine with the right t-stat. if the new t-stat dont work pressure test it.. then that will tell you for sure if you have a leak someplace.

you checked hoses right? had one drip at the rad really slow and not collect water. it would evap from the heat..

korn111685

i also flushed mine a few times to get all the "gunk" out..

when does it seem to run hot on you? just at idle and stop and go? or does it run fine and just after a while starts to run warmer?

toyota4x4907

Perhaps you didnt bleed the air out of the cooling system when you did work on it, so the trapped air was taking up space, but eventually its finding its way out and making your radiator look low.

calderondean

Tnx guys ill double check everything I might have missed something :-) I really appriciate the help ! if you guys have any other ideas pls let me know, ill rebleed the system to make sure, Im getting the new t-stat tomorow wish me luck !

iamsuperbleeder

may be as simple as the radiator cap

a bad one will let too much expanding water into the overflow tank and, well, overflow it, therefore causing a loss of coolant

and pressure raises the boiling point of a liquid, and with a faulty cap not holding that pressure, it could also be the cause of the overheating


Just something simple you might want to think about too

calderondean

thats what I think happen when I lost some of the coolant cause it was boiling over to the resevoir, it has a new cap that I put in a few days ago but its a after market cap, ill buy an original cap from the dealer to make sure TNX !

calderondean

keep the info coming ! im willing to try anything LOL !

toyota4x4907

Is it actually boiling over or do you just mean its being forced into the reservoir? IF its boiling, it doesnt sound like you have enough anti-freeze. You need at least 50/50 mix, where 60/40. anti-freeze/water respectively is optimum.Anti-freeze lowers the freezing point and increases the boiling point. The cap suggestion sounds pretty good too.

YFZsandrider

+1 on air gaps in the coolant. I had a Mazda pickup once(yea, I know save the jokes!), after doing a head gasket in it, and refilling the radiator, it would run fine for 5 or 10 minutes, but the first long trip, and the coolant temp started climbing. My clue was that the heater would blow cold, even tough the temp was hot. That large air bubble allowed the coolant to boil over.

calderondean

I used premixed 50/50 coolant after replacing the water pump, it was boiling in the resevior because of pressure from the rad escaping to the resevoir tank and thats where some of the missing coolant went cause when I looked into the tank it was full of coolant but when it cooled down all the coolant in the resevior was gone and the rad was a little low on coolant. I hope it is the cap too !

calderondean

ill put in the new t-stat & cap today and make sure that I bleed the system, hope it fixes the problem :-)

toyotatom93

I had the same issue, but mine was a head gasket leak. Stopped losing coolant after I replaced it. I never had any leaks either, just lost coolant and could smell it once in a while.

calderondean

okay I put in a new dual stage t-stat, original toyota rad cap, replaced the fan clutch and upper rad hose, bled the system as much as I could,put new 50/50 coolant, new water pump, the rad is only about a year old, what the hell is goin on now it stays cool when its moving dosent need to be fast but if I stop for about 10 to 20 mins. it will start to get hot but atleast it will get cool right away when I start driving, the other day when it got hot it stayed hot at least some improvement. HELP LOL !

calderondean

could it be the radiator ?

YFZsandrider

Well, for one thing- if you start the motor and let it warm up, then with a rag or towel, pop the radiator cap and if steam is coming out, then you've got air in the system, allowing it to boil(or to a lesser degree, it will make some serious steam).

Even if you fill your radiator after having the coolant lines exposed, you may, and propably will still have some good air pockets in the system. So run the thing with your heater blowing, and let the temp get up, but not dangerously high. Then turn it off, and carefully check the radiator level. Top it off if necessary. It might take a few attempts to let all the possible air gaps surface through the radiator.


Also, while doing this, check to see how hot the heater is blowing. If that temp guage says warm or hot, and the heater is blowing cool, the you've got a pocket of air that just happens to be in the heater core.

toyota4x4907

How are you bleeding it? Keep the cap off, elevate the front end if you are able to ( make the radiator the highest point in the cooling system) and let it run for a while, adding coolant when needed. It takes a while usually so be patient . Maybe try 60/40 mixed coolant.