Just a couple thoughts here. First, I don't really see why everyone is immediately jumping on the thermostat as a likely cause here. If it was stuck closed it would be running hot, without question. But the OP said it wasn't. It might be as simple as the deterioration of the plastic on the radiator neck. And if some of it was broken off in the hose, yes it definitely needs to be replaced along with the hoses and a thermostat for good measure. But, my advice would be to keep a close look on it after all that is done. My first thought when I started reading this was, head gasket blown between combustion chamber and cooling jacket. That would be pumping compression into the cooling system and the extra pressure could have blown the hose off. But, I went back and reread the OP and saw that this is a V8, so it's not nearly as likely. But it's still a possibility. Under these conditions it could have excessively high pressure in the cooling system without running hot if it hadn't been driven very long. My point is, after you've done all the repairs, keep an eye on it. Or have it checked just for good measure. Good luck. I hope my suspicions are totally unfounded.
Top radiator hose came off...
- Thread starter jamesewells
- Start date
xtremewlr
Member
Keep in mind this thread was started in 2018 and the OP never posted if replacing the radiator and hoses fixed his issue or not.
[MENTION=29796]jamesewells[/MENTION], if you still frequent the forum, maybe post an update to this?
That's pretty funny. I usually check for that. Oh well, I guess we'll never know.
Since I revived this thing yesterday, here's my situation... My truck literally had a "new" (156K) motor installed last week, because I blew the motor a month ago. When the motor blew up, the same hose was popped off but it overheated really bad on the highway and then the truck died before I could pull over. Fast forward a month, I've got my truck back with the "new" motor and 50 miles in the dang hose pops off again!
It's done it twice to me now, each after about 10 minutes of driving. I went ahead and bought new hoses, new clamps, and a new radiator today at Advance Auto, and I'll be replacing all of that tomorrow and putting in fresh coolant. I don't know what thermostat the shop used, but I really doubt the thing went bad in 50 miles or less lol. Also replacing the pressure cap just in case.
My buddies are stumped, we figure it has to be either a plugged hose or plugged radiator. What I don't get is that the shop ran it at idle for three hours before picking it up, and drove it 30 or so miles, and it was fine.
It's done it twice to me now, each after about 10 minutes of driving. I went ahead and bought new hoses, new clamps, and a new radiator today at Advance Auto, and I'll be replacing all of that tomorrow and putting in fresh coolant. I don't know what thermostat the shop used, but I really doubt the thing went bad in 50 miles or less lol. Also replacing the pressure cap just in case.
My buddies are stumped, we figure it has to be either a plugged hose or plugged radiator. What I don't get is that the shop ran it at idle for three hours before picking it up, and drove it 30 or so miles, and it was fine.
xtremewlr
Member
Before you install the hoses back on, pull the thermostat housing and make sure the thermostat jiggle valve is at 12 o'clock. And order the constant tension hose clamps from toyota.
I'd be curious if the inlet neck on the radiator was still intact, ie, is it all there and does it still have the bulge on the end of it. If the end part with the bulge has broken off it would be very easy for the hose to come off. Ideally I'd want to put a pressure gauge on the radiator and see how high it's going. Replacing the pressure cap is a good idea. If it does it's job the pressure should never get high enough to blow a hose off. Let us know how it comes out.
Update:
Monday I replaced the radiator, both upper and lower hoses, thermostat and pressure cap. Seems to have solved the problem, I'm at about 60 miles driven since with no issues whatsoever. I believe the problem, as the post above this mentioned, was the "inlet" part of the radiator where the upper hose is clamped, the one which moves coolant out of the block and back into the radiator. That part of the radiator was badly corroded, a white/gray color, and had no more lip for the hose clamp to grab. A buddy of mine thinks that it could have been ruined when the truck overheated, probably by the PO. Especially when compared to the radiator outlet on the lower hose, which was still in good condition and had a lip, this seems to have been the issue. I'll try to post some comparison pics for anyone else once I figure out how to add them.
Thanks for the help y'all!
Monday I replaced the radiator, both upper and lower hoses, thermostat and pressure cap. Seems to have solved the problem, I'm at about 60 miles driven since with no issues whatsoever. I believe the problem, as the post above this mentioned, was the "inlet" part of the radiator where the upper hose is clamped, the one which moves coolant out of the block and back into the radiator. That part of the radiator was badly corroded, a white/gray color, and had no more lip for the hose clamp to grab. A buddy of mine thinks that it could have been ruined when the truck overheated, probably by the PO. Especially when compared to the radiator outlet on the lower hose, which was still in good condition and had a lip, this seems to have been the issue. I'll try to post some comparison pics for anyone else once I figure out how to add them.
Thanks for the help y'all!
jamesewells
Member
It fixed my issue because the neck on the radiator had broken.
On the same note, what kind of radiator pressure are y’all seeing on the 2UZ motor? As far as “squeezing” the hose when motor is hot goes, my upper and lower radiator hoses are pliable but feel like they’re holding more pressure than I’m accustomed to, and more than my buddies V6 Tacoma that I was comparing to.
I drove it for an hour today on the highway with no issues and no overheating, just feel like it’s holding a little too much pressure.
I drove it for an hour today on the highway with no issues and no overheating, just feel like it’s holding a little too much pressure.
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