elkdog

Hey guys. new mwmber and i must say, this is probably the best run and most informitive site i've ever been a member of. glad i was accepted. but anyway, i have a 93 4x4 with a 22re, and if i get in and drive the truck WITHOUT moving the temp selector to heat, everything is good. after the truck is warmed up and i move it to heat the temp gauge reads about mid way. if i get in and put the selector to heat and keep it there the needle on the gauge almost goes all the way to the red mark and then slowly goes to about mid way after a couple of minutes.

i've done the thermostat thing, i've done the flush with the lengthy burping afterward, now i don't know what to do. this started about 4 years ago and then i had a head gasket fail, had everything fixed but this problem still happens. any clues?

Elkdog

regularguy412

Did you use an OEM Toyota bypass thermostat? It's really 2 thermostats in one, with a smaller bypass valve in addition to the normal, large bypass valve. The smaller one opens at a lower engine temp. Toyota came up with this solution to help correct the very problem you describe, because the 22r-re's don't have the usual hot wate bypass hose.

Hopefully, your headgasket isn't on the way out, again. Others have noted that spiking temps have been an early sign of this problem.

Mike in AR

Funk_Runner

Have your cooling system checked for combustion contaminants to rule this out.

eric-the-red

Like Mike said replace the thermostat first, part # is on this site. While you're there read the rest of Roger's info, he knows a lot about the 22re and 4Runners.

http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

elkdog

thanks for the info! i'm pretty sure that the t-stat looked like the bypass but i'm not sure of the p#, even though i got it from toyota. i know it was like $10 or less, not around $30 so i'll look at getting another one. i'll let you know what happens!

Elkdog

Teuf

my pre head, and head gasket change, thermostat did the spike thing. The reason i pulled my head was a broken off spark plug, sent head in to get it serviced, discovered cracks in exhaust side, anyway all back together timed it and alls good, cept? the thermostat is a 180, non toyota, runs very cool, was wondering if that would affect my idle

TNRabbit

These engines are designed to run at @ 190-195 degrees optimum, so if it's running cooler it will affect some of the coolant temp sensors, one being the idle, and may also make the engine run rich.