- Thread starter
- #21
Should I put the temp sensor on the upper or lower radiator hose? Or does it matter?
1KZ-TE cooling issues
- Thread starter Birdseyedavis
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Oh man, definitely hear that, been there plenty myself.
Mine's a '96 as well, and if(when....) I have the head off, that's another one I wouldn't put the original head back on even if it looks fine when pulled. These earlier 1kz's have 100% incidence of cracking the head. Later heads have this issue solved, and I would definitely save up and put one of those newer revised heads on, even if the head isn't the problem at the time.
(Ironically, on of the reasons I bought my Prado was because I was sick of dealing with Subaru head gaskets......)
You might mentally prepare yourself for the idea that it's your head that's cracked and not just a head gasket.
If I'm remembering right, coolant flows out of the top hose to the radiator, bottom hose is return to the engine. That's where I'd put it, top hose.
Make sure you purge air from the thermostat area when refilling. Refill from the heater hoses or make sure you have a thermostat with a vent(drill a hole if not) and have the vent pointed up to purge air. Air locked thermostat= thermostat doesn't get up to temp = no coolant flow when needed = kaboom.
- Thread starter
- #24
Gotcha, I got the Toyota oem 76 deg C thermo. It has the little vent in it. I put that at the top. I put the temp sensor on the bottom hose mainly because that was where I was having issues (bottom hose never got hot). I filled everything back up but I still have the same problem. Top of radiator is hot, bottom is cold. My in dash temp gauge got to normal operating temperature but the new sensor moved 1 degree from 72 to 73.
Bottom radiator hose is after the coolant goes through the radiator and gets cooled down, it may not get warm just sitting there at idle. Is your heater blowing warm air? Heater hoses getting warm? If so, coolant flow is fine.
- Thread starter
- #26
I’ll check the heater hoses tomorrow. Thanks again for all the help!
- Thread starter
- #27
Sitting with the idle up on: Heater hoses are hot, regular gauge gets to operating temps, and lower hose is cool. Took it for a short drive (3 times around the block): regular gauge stayed at normal operating temps and lower hose got to 98 degrees. I think I’m ok for now. Gonna take it on a longer drive to see what happens. Gonna have the oil tested to confirm blown head gasket. In the mean time gonna start another thread because now I have another issue! Can’t win for loosing!
AussieHJCruza
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You want to be testing the coolant for combustion gases, not the oil, to confirm head/HG issues
- Thread starter
- #29
Yes, I will do the block test but I read on another forum that it can be inconclusive due to diesels having different exhaust gases than a gasoline engine. Blackstone industries will test the oil for coolant. Thanks for the help!
AussieHJCruza
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The last couple of blown HG I've had through here have had perfectly clean oil hence the coolant suggestion, but oil analysis is never a bad thing.
All the test kits I've used say they work on anything, but might depend on how that particular test works I guess
- Thread starter
- #31
Gotcha, thanks for the help! Time will tell!
Following this thread with interest, I'll undoubtedly be going down this path at some point. Just hitting 100k miles on my 1KZ. Might have gotten lucky and the head already popped and was already replaced by the previous owner, but not sure how to check that.
I've even given serious thought to buying + stashing a head and gasket set proactively. Given the way the universe frequently works, that alone might mean my head never goes bad.
I've even given serious thought to buying + stashing a head and gasket set proactively. Given the way the universe frequently works, that alone might mean my head never goes bad.
