rdharper

Sanity check me on this (the '85 22rec below);

1. vehicle heating is perfectly normal except for the last 1.5 miles before the driveway, where the driving is 1st gear (and 4wd), going from 200ft to 1750ft elevation. So this is the only go-slow with signficant load we encounter.
2. Overheating means, where 1 is red, 5 is cold, and 3.5 is normal... so overeating case is 2.5. Not severe but not normal. Letting it idle brings the temp to normal in about 4 minutes.
3. No coolant loss. Coolant is clear and a year old.
4. Temperature at the top of the radiator is 208F.

Truck runs beautifully in ever other respect. Good pickup, good mileage etc. Also, just passed california smog2 with good numbers.

After doing all the reading, all of this suggests the fan clutch. So I got it hot (2.5), stuck a leather gloved finger, and, I could stop it, although it wasn't a free-wheeling situation as it is when the motor is cold.

So am I right? Fan-clutch?

At this point I'm going to have it done on Monday, as I can't think of any other likely case. Comments welcome, please.

85toy

you should always be able to stop the fan clutch i believe, but i may be wrong. all those things you said seen normal to me, i know my old truck(not toyota)used to heat up on the uphill before my driveway when i had to go in 1st gear. i dont know for sure but it all sounds good to me.

rdharper

Ok... this truck only does this when the ambient temperature is above 85F. But it never did it to this extent, something has changed.

But you could be right about always being able to stop the fan clutch. I don't know. I've read various comments in all the many threads on this subject. There are a lot of different opinions as to how hard the clutch pulls in when the engine is hot.

You may also be right about "maybe you shouldn't worry about it". I don't have much to worry about these days, so I find myself worrying about trivial things. But something has changed. And I have read enough opinion about being sensitive to any overheating, among other things.

I've also thought of getting a pressure tester... no leaks, so not much else to check. Pump must be working as otherwise it wouldn't come down to normal while idling, and fairly quickly.

Lastly, won't hurt to shell out for a new fan clutch. I don't think its ever been replaced. (but I'll continue to worry anyway)...

85toy

also just thought of this my old truck was working just like yours is but then one day it started getting wrse and worse until it was overheating everyday. it turned out to be the thermostat, i would check that. and its only like a $10 dollar part so cant hurt to change.

MudHippy

If you notice any fluid leaking out the back of the clutch, that's a sure sign it's toast. I would be concerned about being able to stop mine when it's fully engaged. But I have the 3vze to deal with, and it don't likes the heat, so I stays on top of it. The cooling system maitainence that is. No room for doubt, if ya catch my drift.

rdharper

I've also got a 3VZE, so I get your concern about that engine. Mine is rock solid temperature wise, but I watch it carefully as well.

I just thought of one change I did make in the '85 22rec. Earlier this year I switched from Toyota coolant to Prestone. I never bought into all the conviction to stay with Toyota's overpriced product. I understood all the arguments before I made the switch.

But this is the first summer since that switch. Can't be that. Naw.. can't be. Hmmm.....

rdharper

Ok, will do. And maybe make it the "overshoot" type.

corvettelvr73

My 85 22re starts over heating when I'm trying to get it at 70 MPH with the aurto tranny.

85TurboRunner

My '85 Runner use to have a problem of getting hot to the point of water boiling out of the radiator when I'd be in 4wd going up hills. I happened to have an extra radiator laying around so I swapped it in place of the old one and never had a problem again.

rdharper

Current plan is to swap out the fan clutch, put factory coolant in, and the overshoot T-stat (if they've got it in stock)... on Monday.

Fan Clutch has never been replaced, so it can't hurt at this mileage.

As I've said, this overheating problem (half-way from normal to red), occurs only in the last 1.5 miles to home, in first gear (or 3rd 4wd), with ambient above 85.

Last night I went to town, picked up 50gals of gas. As I approached "the hill", I left the lights on, added the running lights (another 2/10ths hp load), all accessories on. No overheating. Ambient was 75F. If I'd done this 2 hours earlier, it would have done the overheating trick as described earlier.

So this is repeatible. Next week I'll know if its fixed.

Thanks for the comments.

rdharper

Well its fixed. Fan clutch did the trick. Load test (uphill, ambient above 85, lights on, in first gear) passed big time. Temp gauge never budged.

I replaced the coolant with Toyota pink, no T-stat change as they didn't have the overshoot-type.

So I'm a happy (and lucky) camper.