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My Motor Runs Hot and I've changed everything

1K views 22 replies 17 participants last post by  85Surf 
#1 ·
1985 Toyota 22R. Just wanted to know why my motor runs hot and if it is a typical secenario. My temp guage operates correctly so I know that isn't the problem. The temperature usually reads about 2/3 to 3/4 up the temp guage so I know that is a little too warm. Usually should read about 1/2 way or maybe a bit less. Changed out thermostat to a high quality one. Helped, but didn't solve the problem. Running 50/50 coolant. More water than coolant makes it run hotter. Pressure tested radiator cap, holds great. Radiator flows good, pressure tested that as well, no leaks. Brand new water pump. Hoses are all in good condition. Motor is bored .030 over and I have a 38 DGAS and the mixture is definetely on the richer side so I know that it is not running hot due to a lean mixture. I know the head gaskets on the Toyotas like to blow when they get hot so I need to get it fixed before this one goes too. Thanks
 
#4 ·
Have you ever soaked the radiator with water after it's warmed up? It should evaporate the water evenly. I had a bad / plugged radiator once, the way the water evaporated made the radiator look striped, one channel didn't heat up at all. If it's only slightly plugged it could have a marginal condition like yours.
 
#6 · (Edited)
hawaii500_1999 said:
having your carb jetted too rich can make it run hotter than normal. i experienced that but usually only under a load i.e. up hill or loaded down with crap.

Not a chance .. the richer the mixture the lower the combustion temps.. the leaner the mixture the hotter th combustion temps...

At what point is it running hotter?? While going 70 down the highway or sitting in traffic.. or just all the time..

I Had one 22re that everything was perfect.. new three row, new everything and it still ran hot.. Came down to having a cracked head.. right near the #2 exaust port.. did not leak any water at all.. Put a differant head on it and it was fine.. Another thing.. you say the raditator flows good but are you sure it does not have a build up of crud.. they can still flow water and not transfer heat ... If you are having a problem with it running hot at low speed I would Guess A fan clutch too... many differant things could be doing it... Process of elimination:D
 
#7 ·
is it a stock temp gauge? if not how do you know it is running hot?what temp thermostat are you using? I noticed with a 195* stat it would run just over 3/4 mark but a 180 sent it down to under a 1/2. but being I have a stock temp gauge I have no I dea what it is actually running.
 
#9 ·
Havent checked the fan, but that could be a possibility. Everyone keeps talking about a fan clutch but I was under the impression that if the fan spun, it is sucking air, thus cooling the radiator. How do I know if the fan clutch is bad? Motor doesn't get hot in traffic but rather on quick accelerations and going down the highway. If I was to drive on the highway more than twenty miles, guaranteed it would overheat. I know that the head isn't cracked because I had it rebuilt and everything so it was thoroughly checked for cracks. The thermostat is a 180 which Toyota recommends. Should I just get an OEM thermostat and maybe that will help? My thermostat I have now is one of those 10 dollar good ones so I'm pretty sure it is working correctly. Thanks for all the suggestions, if you have any more that would be great.
 
#10 · (Edited)
My guess from what you are saying is you have a A radiator that has lost its abillity to cool. when you are cruzing at high speed the fan does not do much.. the air for the most part is force fed. Are you sure the head was pressure tested.. It is often overlooked.. Most heads that are cracked look great but under a pressure test they show up as cracked... anyways You may have a radiator that is half clogged with crud reduceing heat transfer.. That is what I would be looking at closely...Pat
 
#12 ·
Pat said:
My guess from what you are saying is you have a A radiator that has lost its abillity to cool. when you are cruzing at high speed the fan does not do much.. the air for the most part is force fed. Are you sure the head was pressure tested.. It is often overlooked.. Most heads that are cracked look great but under a pressure test they show up as cracked... anyways You may have a radiator that is half clogged with crud reduceing heat transfer.. That is what I would be looking at closely...Pat

i too agree with pat, the radiator may flow but unless it can contact the outer wall of the radiator it self it will not cool well at all.


cliff
 
#13 ·
I had the EXACT same problem less than a month ago. Around town, or under load it would heat up.......ideling it would stay cool. I replaced everthing as well. The radiator even tested fine under pressure, but just wasnt flowing right. Since it was a late Sat evening with all the rad shops closed, I hit Pep Boys as a last ditch effort and low and behold, they had a brand new replacement 3 core for $180.00 or so. 20 minutes later it was in and it has never seen over 1/2 of the temp guage on my 38 mile trek to work at 70mph. Before, I would have to run the heater on high to keep it from boiling over. That sucks in south Texas heat. It stayed that cool (less than 1/2 on the guage) on a 95+ degree day in the rocks as well.

Replace the radiator, my friend.
 
#15 ·
tuckn18s said:
Havent checked the fan, but that could be a possibility. Everyone keeps talking about a fan clutch but I was under the impression that if the fan spun, it is sucking air, thus cooling the radiator. How do I know if the fan clutch is bad? Motor doesn't get hot in traffic but rather on quick accelerations and going down the highway. If I was to drive on the highway more than twenty miles, guaranteed it would overheat. I know that the head isn't cracked because I had it rebuilt and everything so it was thoroughly checked for cracks. The thermostat is a 180 which Toyota recommends. Should I just get an OEM thermostat and maybe that will help? My thermostat I have now is one of those 10 dollar good ones so I'm pretty sure it is working correctly. Thanks for all the suggestions, if you have any more that would be great.
its not the fan its the radiator.change it
 
#17 ·
what if guage reads hi at start up and stays ther

till i turn engine off.



it sarted in Jackson,
got pulled over and re started 4runner and WTF all of a sudden its very dark

out side and all seemed o.k so i drove the 40 miles home and all o.k

so 3 rubicon trips later its still on red crazy hot zone till i turn it off.

new sensor installed too***

new wire soldered on for sensor connection (old one was all twisted on ) ***

whats the fix all.:confused: :mad: :confused:
 
#18 ·
Re: what if guage reads hi at start up and stays ther

4RUNNERJADE said:
till i turn engine off.
it sarted in Jackson,
got pulled over and re started 4runner and WTF all of a sudden its very dark
out side and all seemed o.k so i drove the 40 miles home and all o.k
so 3 rubicon trips later its still on red crazy hot zone till i turn it off.
new sensor installed too***
new wire soldered on for sensor connection (old one was all twisted on ) ***
whats the fix all.:confused: :mad: :confused:
Speak English much???

If the gauge is reading high (do you mean pinned to the top???) all the time, then either the sensor or gauge is bad, period. If you had an engine running that hot that long, it would have exploded in your face already. Get a new sensor, new sensor wire, and new gauge cluster. OR, go aftermarket for the sensor and gauge.
 
#19 ·
Re: Re: what if guage reads hi at start up and stays ther

Pazuzu said:


Speak English much???

If the gauge is reading high (do you mean pinned to the top???) all the time, then either the sensor or gauge is bad, period. If you had an engine running that hot that long, it would have exploded in your face already. Get a new sensor, new sensor wire, and new gauge cluster. OR, go aftermarket for the sensor and gauge.
LOL! Jade, he's right, you don't type in english a lot of the time bro, thank god you don't talk like ya type! Try typing like ya talk, it may help ... :flipoff2:
 
#20 ·
go by a radiator shop

Ask to see if your guage is bad and they should have an infared temp gun and can check if the radiator is working or if the guage is bad . I got one and my 85 exccab with v6 radiator guage use to be half way which on my thermo said about 170 . And in the past I've check the guage vs my thermo and most of the time the guage will read higher to probably scare people . good luck
 
#23 ·
Thanks all (I Meen Thank You All For your information)

:D :D

the guage cluster only sais 89K thow,;)


I'll go ask chris about that other SR5 Cluster .


Thank You All For the Info Also.:D
 
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