My 22R with 3,000 on a rebuild has been running too hot. The factory gauge was way off but I could tell by the heat the engine was putting off. The new thermostat wasn’t testing good enough so I replaced it with a 180, which tested as good. And put a new Auto meter gauge in the thermostat housing. But it went straight to 260 degrees in five minutes. So I bought a new meter from O Reillys but it read the exact same thing, 260 in 5 minutes. The upper radiator hose not getting real hot. Then I did a leak down test. All cylinders at about 4% loss. No water in the oil. No air pockets. Radiator passes water through quickly, fairly new. All I can think to do now is to get a thermo sensing gun ( forget what they are called). Can anybody recommend a good one? Any other potential issues? Many thanks

 

what is the condition of the cooling fan? it's factory and not a flex fan?

 

The temp gun from Harbor Freight is good enough. I’ve confirmed mine pointing it right at the thermostat housing. Reads just about what the thermostat rating is.

 

Thanks for the replies, I just found out my antifreeze smells like gasoline so am on my way to Harbor Freight to get a coolant tester.
I have heard those HB heat guns work well too. I haven't got one yet but might still get that.
The fan is stock but I think I replaced it years ago (it sat for 12 years) and it's not OEM but is similar. It turns all the time, and seems to turn
fast enough but I was wondering if the eye could tell if it was fast enough.
Next question is, if it has exhaust in the coolant, does that mean its got a bad head gasket or could it be from some tube or something.
I can't remember what all is bolted to that exhaust manifold, is that water pipe from underneath the intake (this is carbureted) going to the exhaust? I'm
not in the same county as the truck today.

 

I did a test that sucks air from inside the radiator, and there’s no exhaust in the coolant. ( fluid stays blue). Will get a temp gun next. Pretty sure I replaced water pump when I rebuilt it. I loosened the belt and it turns very smooth.

 

Could the gauge sender be blocking the thermostat from opening? Is there pressure in the upper hose? 260 at the housing but not too hot at the upper radiator hose suggests to me the tstat is closed. There's also the heat spike issue with these motors, but if that's going on the tstat opens eventually, probably before 260.

 

I was worried about that sensor blocking the T stat so I took the Tstat out a few days ago. I figured it might overheat a little but not enough to interfere with troubleshooting this bad of a problem. I just found the problem. I found an old Aisin fan clutch, swapped it in, and now it won’t go above 110. ( T stat still out). Both of the clutches had the same resistance as far as turning the two halves, but the Aisin spins faster anyway. I can tell because the Aisin fan spins in one thin blur whereas the old generic one was showing the blades individually ( barely). So looks like osv was right.
Thanks for all the help

 

Having gone to 260* a few times now, i would watch your headgasket closely. I have no real data other than having bought several overheated Toyotas needing head gaskets back in the day. Not sure what exactly it takes to kill one.

 

[QUOTE=Melrose 4r;52502627]Having gone to 260* a few times now, i would watch your headgasket closely. I have no real data other than having bought several overheated Toyotas needing head gaskets back in the day. Not sure what exactly it takes to kill one.[/QUOTE

yes, overheating may have caused the rings not to beak in right. Just drove it 30 miles, looks like it’s still using a quart per 60 miles even at 160 degrees. (180 thermostat). Gauge might be off, just a cheap Bosch. But it’s mechanical and plugged in where the factory sensor was. Soon as I turned it off turned radiator cap slowly to check pressure and there was zero pressure. Cap seems stiff enough. Like I said, I did a leak down 3 weeks ago, had 4% on all four.
So am wondering why there was no pressure.
Thinking about pulling the motor. I have a 22RE engine I rebuilt that only uses a quart every 4,000, with 105,000 on it. It’s still in the 94, which I rolled many times starting at 80 mph I guess. Rearended by hit and run driver 6 am on interstate. I was doing 70 but he hit me so hard the tow hitch separated from the frame, bumper crumpled, rear differential hit the T case, both rear main leafs snapped in two. Seat snapped free of the slide and back of seat snapped loose. 7 broken ribs 4 fractured vertebra but no blood no surgery. Landed on the wheels. Back of cab made a good roll bar. I had a buddy tow it back to my place for parts. Still healing but walking fine.
So, still want to figure out the problem