tomh

On Toyota thermostats, is OEM much preferred over say, NAPA parts?

I watched the temp gauge today, and even at its highest level--3/4 up, it was still blowing cold. But like you say it could be circulating so fast it does not have time to warm up.

Thanks

tomh

searching answered my own question, an OEM t-stat is on the way tomorrow. i may do a flush on the cooling system and backflush the heater core too.

thook

I use a Stant brand...NAPA...and it works fine. I just drilled a hole in it to offset temp guage overshoot. I put the money saved elsewhere.

I should have asked if you had heat. I'd thought of that the other day. The thermo sticking open would delay the AAV shutting. Glad you figured it out.

abecedarian

It kind of sucks that Toyota didn't catch that temp 'overshoot' problem. They seemed to have done well on the cooling system on my 89 celica with the bypass to the heater core... wonder why they didn't do a similar thing with the trucks?

@ thook:
As for drilling that hole... is there a recommended size for the hole? Say 3/32", 1mm, etc?
I ask because I've got a '91 p'up with a stant thermostat- one diaphragm and a 'jiggle valve', and I don't have the overshoot problem.

slisdexia

Last toyota I had always blew cold air even though the gauge said it was warmed up. So I double checked the radiator, installed a "T" connector into the line to the heater core... and blew nothing until a big KA-CHUNK and out came a rust colored turd! Then it was like new! No more problems.

slisdexia

by the way, the water from the hose blew the turd out, not me

tomh

many a problem has been solved by a good dump!

thook

I don't know. I'm sure they don't know, either....lol!

They did issue a TSB on it in '87. I found out about this whole thing on 4crawler's site a while back. Here's what his site quotes from the TSB.

It says:
Some 1984 pickup trucks and 1983-1984 Celica models, equipped with 22R-E engines, may experience a condition called "temperature gauge overshoot". After starting a cold engine the temperature gauge will indicate a higher than normal engine temperature for a short time just prior to the thermostat opening. After the thermostat opens, the temperature gauge will return to the normal range. A new double valve thermostat has been made available to reduce temperature gauge overshoot.
And calls for part number 90916-03070 which according to the TSB replaces 90916-03055

4crawler mentioned using a 1/16" drill bit....or so. I would imagine 3/32" would work, too. Not much bigger at all. I'm not sure what size I used, though. I just grabbed a tiny bit and went to town. Works fine. I didn't have overshoot much....just when I used the heater in the winter.

abecedarian

I have to say

tomh

well I am keeping my fingers crossed that the t-stat is the major issue here. I have one coming to the dealership tomorrow. And a new radiator cap since the one on there has seen better days. guess we will see if any turds come popping out! hopefully just out of the truck...

abecedarian

Okay... I don't want pic's of that.

tomh

AAHHHHH.
SHould have left it alone. So I go to replace my thermostat. Found one of the bolt holes was stripped out and the bolt was held in place by RTV. That was the good news. the bad news is the other bolt was stretched, and broke off with minimal effort. Now of course the easy out is broken in the hole i drilled through the bolt. WARNING: Do not use Smith and Wesson made in taiwan screw extractors. I am an idiot for believing the tool store guy. the steel in that thing is soft enough to snap with little torque, but too hard to drill with a cobalt bit.
I am hoping I can get a nut on what is left of the stud and weld it on and hope that does it. if not I will have to take the manifold off and go from there.
I am way old enough to know better, and I predicted this every step of the way. Just glad I have another truck. DANG IT!

gcoryell

I had high idle problems, as well as 'cycling' idle problems on my 92 2WD pickup 22RE. The cycling was affected by having the A/C on, as well as having the brake pedal depressed. It was quite confusing. The eventual fix was to diassemble the auxiliary air valve and clean out the gunked up coolant that was blocking coolant flow. The lines feeding to and from the AAV were also blocked partly, so I replaced them. The smoking gun ended up being the small vertical pipe that sticks out from the thermostat housing--it was plugged with Teflon tape as well as sticky coolant. The diameter is so small that it is very easy to plug. This vertical pipe connects to one of the lines that feed the AAV. Be careful disassembling the AAV, as it is easy to strip one of the Phillips head screws. Lastly, don't forget to measure the extended length of the piece of the AAV that is on the air side--it needs to be reassembled so that distance is the same (assuming it was correct in the first place). Clean all the carbon gunk out of the air bypass ports of the AAV. If you still have high idle, think about changing the screwed in length of that piece of the AAV that is opened and closed with the thermostatic spring. More air bypass equates to higher rpm.

One last possibility is your cold start valve. If it is very gunked up, it could be sticking or not closing all the way. This would potentially put too much fuel in the manifold during cold starting, even pooling it on the upper plenum floor. I sent out all five of my fuel injectors to be ultrasonic ally cleaned and flow-matched. My truck immediately ran smoother after I installed the matched, cleaned injectors.

Fundy Rider

I have a 94 extra cab 22re and have a similar condition that used to be worse until I got the thermostat from the turbo 22re. It has a small hole as well as the regular coolant passage hole. It helped somewhat but in the end I think it is just part of the 22re. Mine climbs to around 1900 rpm and slowly makes it way down to a normal Idle. It used to be around 2200 but then again that was in the winter and it has always made me wonder if there is a peace of metal that acts as a thermo switch to open the aav more or less in colder or warmer weather. Maybe I think to much?

gcoryell

Yes, you can adjust the AAV when it is disassembled to have it admit more or less bypass air. This is likely the solution for folks with high idle problems, assuming they have no other intake leaks and assuming that coolant flow to and from the AAV flows freely. Intake leaks on the 22RE are pretty easy to identify--they usually sound like a very high pitched whining noise.