I recently replaced my head gasket. All is good, but the other day my engine got hotter than normal for a little while. I immediately pulled over and turned it off and when I started it back up it ran cooler. I figured the thermostat had stuck. I have been putting autozone thermostats in and I didn't even replace it when I did the head gasket. So I decided to replace it with a Toyota thermostat.

At the dealership, the girl at the counter offered two different temperatures. I don't remember the temps, I think she said them in degrees celcius anyway. I picked the hotter one. I'm in Texas and summers are very hot.

When I got the thermostat I could tell it was built much better than the autozone special. However, when I drove the truck after installing it I thought the engine was overheating for a while but I think that the thermostat is just that much hotter. I don't have a guage with the temperature on it but I'm used to the guage staying less that a quarter of the way up. Anytime it got over a quarter, it meant it was about to start climbing.

With the new thermostat it sits almost half way on the guage. That bothers me but I'm afraid I'll just have to get used to it or go get the colder thermostat.

Does anyone have any relevent information about the temperature range of the temp guage or about the toyota thermostats or anything else you think I should know about this stuff?

 

a little under half is normal.

 

I always get the 180 degree tstat. My engine pinged like hell with the 190 in there, but is perfectly happy at 180.

 

mine seems to run fine at that temp. If it doesn't go over half way I'll keep the hot one. I guess I'm just surprised that that small difference in temps looks so big on the guage. I've been thinking about making my own instrument panel with aftermarket guages. Maybe then I could see what the temp really is, not to mention oil pressure, RPM, etc.

 

This seems to be a "hot" issue. no pun intended

From your sig (join date) it looks like you may not have driven your truck in the winter yet?

Anyway I just spent the first month or two of my first winter with my truck trying to figure out why the temp gauge would climb to right below the red, then drop to normal then fluctuate between middle warm and cold. My truck always ran at a 1/4 mark on the temp gauge, even in traffic in the dead of summer. Why was it running hot in the winter?

Turns out the heater core feeds off the the coolant system before the thermostat. Therefore the engine thinks it is running cooler than it really is and the thermo takes alittel extra time to open.

You need a dual stage thermo to fix this. It allows a little coolant through beofre opening the main stat. It fixed my problem and me truck now runs at a 1/4 mark as usual.


Desconcedo helped me out with this. Big props to him for solving my mystery. Here is the link to part you need. I ordered it through toyota, the part number is correct. Dont forget to get a gasket with it. The part is 34.00 throuhg toyota and the gasket is 7.00. http://www.4crawler.com/4x4/CheapTri...tml#TstatOrder

Hope this helps

 

My stock water temp gauge doesn't move higher than 1/2 way until the coolant is over 235* F. By that time its already too hot IMHO. I consider the stock gauge to be a fancy idiot light. I think I'd rather have a red idiot light because it would get noticed faster.

 

X2
Bigblock

 

I drove four hours to the coast and back over the weekend and it never went over half way, but it did ping a little bit. That would be solved by using higher octane gas but it would be cheaper to get another cooler thermostat.

Thanks for all the info, y'all.

 

About 99% of the time, I will swear by Toyota parts. That 1% I don't like includes the OEM thermostat. It's garbage. I do NOT like the fact that it holds open until your temp goes past normal. Get a Stant and call it a day. I stopped using Toyota thermostats about 15 years ago. Not a fan.

 

Do you mean open until the temp goes past normal on the cool side? Or do you mean closed until the temp goes past normal on the hot side?

 

Yes! Good catch. It seems from my experience with them, that Toyota thermostats remain closed longer than they should on warm up. Watching my gauge, I would see the needle shoot past the normal operating spot, then I guess the 'stat would open and the gauge would fall to normal. With the Stant, the temp gradually raised to normal but did not go past.

I didn't like seeing the truck run hot, even if only on warm up.

 

Yeah, ok. That's a 22r/22re cooling system design problem more than a Toyota t-stat problem. http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

Thanks!! Learn something new every day! I still like the way my stant behaves. I have used them in all my rigs since I worked as a service tech back in the stone ages.

 

I have the stock Toyota thermostat in my Tacoma, and it always goes to halfway on warm up, and stays there.

On the other hand my friend has a 97 Tacoma 3.4L 4x4 SR5, and he has started having trouble with overheating. It happens only when he is going uphill. He was following right behind me and my truck (96 Tacoma 2.7L 4x4) had no problems on the 8 east from AZ to CA through the mountain passes. His truck on the other hand started overheating real bad, and we pulled over to put water in her and let her cool down before we continued at a very slow speed the rest of the way. This happened again today on his way to palm springs he called me and said he was overheating going uphill again. What should we troubleshoot first when he returns? Water pump, thermostat, or something else, and how?

 

Every thermostat I've had has this exact same problem in my 22re.

 

Never had a problem on my 22r or 22re, however I did replace them on rebuilds and was told by the good people at the auto parts store that the more expensive ($12.00 instead of$9.00) of the two would stick open instread of closed. Thats the one I'll take, at least it won't leave me overheated.

 

Not unless you get the special Toyota t-stat designed to eliminate that problem ( TSB: 029032787 22R-E Engine Temperature Overshoot):
- http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

I've been running the same 2-valve t-stat in my '85 for almost 10 years now, it still works perfectly and if I can get that sort of lifetime out of a part compared to only a few years out of a Stant or similar unit, I'll stick with OEM.

 

Is stant a brand name?

 

Yes it is.

 

Yeah, I know of this problem. I just haven't had time/money before to actually fix it...now that I'm actually working I shall do this Should probably buy my expired tag/brakes first