I have a 22re and am aware of the temp overshoot problem with this motor. After doing my HG I noticed that if I had my heater on full blast and I went up a decent sized hill that my temp guage would start to climb a couple needle widths. Usually at the top of the hill or sometimes halfway up the needle on the temp guage would just drop suddenly back to the normal spot. Is this caused by the thermostat paritally closing or could it be a clog/air lock in the heating system? I have read a few articals on this, but noone thus far has had the rising and dropping of the temp guage.


Thanks

 

what kind of t-stat do you have, does it do the same thing with the heat off?

 

...and with the heat on, do you get HOT air or lukewarm or cold? have you pulled the thermostat to see if it performs to spec?

 

i read somewhere that withteh Toyota heater system, your temp will actually go up withteh heater on. Wish i remembered exactly why.

 

I saw a post on here about a month or so ago with the same problem and someone explained that issue (Roger Brown?). He said because of the design of the return from the heater core that is a normal occurance and has nothing to do with the temp overshoot. Mine did the same exact thing and with the 2-stage t-stat and all of the air removed from the system it is better. Do a search I know I saw it.

edit.....
take a look at 4Crawlers page on the issue http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

you should check to make sure that all of the air is bled out of the coolant system; that the radiator & cooling fan are "cycling" &, of course, that the coolant is topped up.

 

check out the link piratefins posted.. its from roger brown's website.... the dual-stage thermostat fixed all the exact same problems i was having on my 85 22r

have had no problems since....

 

Im gonna go pick up that thermostat next week. I also think im gonna have my cooling system cleaning too. I think its starting to get clogged in spots. Anyone have any idea what kinda cost I'd be looking at for having that done? Thanks for all the posts.