[SunGlobes]

I have 91 P/UP; 4X4; 4 cyl.; 22R;......I have the same problem as alot of others from reading this forum: temperature guage overshoot.

As others have explained, when the heater is on, my temperature guage seems to shoot up close to the red mark and just before hitting red, it will drop back down to 1/2 mark. This problem seems to be worse if I'm stuck in traffic or at a red light, etc. Sometimes the only way I can get the temp. guage to go back down is: turn the heat off, wait for the light to turn green, and drive a mile or two allowing the outside air to help cool the fins on the radiator, thus dropping the temp. guage back to "normal".

Now, I've read the post: http://www.4crawler.com/4x4/CheapTri...tml#Thermostat as well as others' comments/suggests on the forum.

Here's my question....

The 4crawler post recommends part# 90916-03070 (local dealership price: $39.50)

verlaryder recommends (on 01-22-2009 "temp guage problem" thread) part# 90916-03083 (local dealership price: $19.25)

So, these are obviously not "the same" thermostat. I originally thought maybe one part # superceded the other part #, but since I was quoted two different prices, I can only assume that is not the case.

The dealership does not have either one of these part #'s in stock, so one would have to be ordered, and I would like to know if anyone else has had this particular problem (temperature guage overshoot) and exactly which thermostat solved the problem.

FYI.....My radiator and water pump is only 2 months old, backflushed entire system before they were installed. I also changed all hoses (Gates) and new worm clamps, installed 50/50 Prestone antifreeze, so I don't think I have a flushing problem, clogged radiator, etc. or any of the other usual culprits.

Not trying to be rude here, but I don't want to hear from anyone who thinks they know what the problem is and wants to post another link as too what the problem is and how to correct it....I would like to hear from someone who has experienced the problem and has corrected the problem.

Thanks, SunGlobes

 

[DCM]

I had the same problem. When I rebuilt my engine, I used a cheaper thermostat and the guage would act as you are describing. I switched to a "heavy duty" thermostat and the guage would move slowly up to the regular position and stay there without fluctuating.

 

[boypilot]

It sounds kinda *******, but pull out the thermostat and drill some small holes around it. This prevents an air bubble from being created under the thermostat, which causes a delay in its opening.

Worked for me, I had the same problem.

 

[el_tarzano]

Had the same problem after I rebuilt mine. I used teh thermostat that the dealer gave me and after a few weeks it fixed itself, dunno how or why I just thought if it's fixed, might as well leave it alone.

 

[fourwd1]

It sounds kinda *******, but pull out the thermostat and drill some small holes around it. This prevents an air bubble from being created under the thermostat, which causes a delay in its opening.

Worked for me, I had the same problem.

I've been telling people to do that for years. It works for the overshoot problem, but more importantly it allows coolant to flow when the t-stat fails, and when they fail they fail to open.

 

[SunGlobes]

Thanks for all of the responses so far guys. I've read about the "drilling the holes" solution and I may use that as a last resort.

I've also thought about using a Stant HD thermostat, as opposed to using a "regular" Stant thermostat.

But, has anybody actually used (or fixed anyone else's truck) using Toyota Part #90916-03083 or Toyota Part #90916-03070, and if so which one and did it seem to fix the problem?

Thanks, SunGlobes

 

[SunGlobes]

The OEM temperature rating for my truck's thermostat is 180*F....I am currently using a 195*F thermostat, because at the time, this was the only temperature rating, in stock, and I needed one right then.

In hindsight, I'm wondering if a thermostat rated for 180*F would solve the problem with the "temperature guage overshoot."

I just checked, online, and my local Advance Auto Parts has an "Optional Replacement" Beck/Arnley Thermostat (Part #143-0687) rated for 160*F.

Does anyone think dropping down to a 160* thermostat would help solve the "overshoot" problem or should I just go back to the OEM rated 180*F thermostat? FYI.....I live in eastern NC, where the temperature is fairly mild, even in winter, so I don't really see a need for a 195* thermostat.

Thanks, SunGlobes

 

[verlaryder]

The Toyota 90916-03083 is a 180 stat and has a dealer suggested retail price of $14.69 but is available for only $10.60 at www.1sttoyotaparts.com. Unlike the Ford and Chevy quality auto parts store stats the Toyota 90916-03083 will last 15-20 years.

With the 90916-03083 your temp gauge will not go higher than 1/2 way up the dial with the heater on and with the heater off it will run about 1/4. Your engine will also be less likely to ping with the 90916-03083; in fact the 90916-03083 was the stat Toyota installed on the turbocharged 22R-E's so that's why it fits perfectly and works fine in ordinary 22R-E's. I've been using the 90916-03083 in my '92 22R-E for nearly all of my engines 486,000 troublefree miles (except for a timing chain replacement at 417,000 miles). Don't forget to also order a Toyota thermostat gasket which is made of a grade of rubber that will seal for 15-20 years (unlike the cheap grade rubber gaskets available in auto parts stores).

 

[sb5walker]

x2 on verlaryder's suggestions.

Actually, the temp rating of the OEM thermostat in the 22re is 190 degrees. It's the 3vze that is rated at 180. However, the 180 deg stat is reported by many owners to work better in the 22re than the 190 - as verlaryder mentioned, the 190 can cause pinging. That's why she recommended the 180 deg 22ret stat.

I would not go with a stat below 180 degrees because your engine coolant temp sensor (ECT) may not send the signal to the ecu that causes it to go into closed loop mode (the normal hot engine operating mode in which the ecu uses signals from the O2 sensor and other sensors to calibrate mixture and timing)

The toyota thermostat has a "jiggle valve" that is supposed to prevent air bubbles from forming. I always use a toyota stat in my 3vze and have no problems, but the stat is mounted vertically, not horizontally as in the 22re. It would be interesting to know if the stat that boypilot had to drill holes in had a jiggle valve or not...

 

[SunGlobes]

The Toyota 90916-03083 is a 180 stat and has a dealer suggested retail price of $14.69 but is available for only $10.60 at www.1sttoyotaparts.com. Unlike the Ford and Chevy quality auto parts store stats the Toyota 90916-03083 will last 15-20 years.

With the 90916-03083 your temp gauge will not go higher than 1/2 way up the dial with the heater on and with the heater off it will run about 1/4. Your engine will also be less likely to ping with the 90916-03083; in fact the 90916-03083 was the stat Toyota installed on the turbocharged 22R-E's so that's why it fits perfectly and works fine in ordinary 22R-E's. I've been using the 90916-03083 in my '92 22R-E for nearly all of my engines 486,000 troublefree miles (except for a timing chain replacement at 417,000 miles). Don't forget to also order a Toyota thermostat gasket which is made of a grade of rubber that will seal for 15-20 years (unlike the cheap grade rubber gaskets available in auto parts stores).

Thanks so much for your response, verlaryder. I will definately take your advice and order #90916-03083, as well as a Toyota gasket. This is a problem (temperature guage overshoot) I have dealt with for several years now and hopefully your suggestions will clear it up.

Thanks also to all of the others who have offered their opinions and experiences. This seems to be a great forum with plenty of knowledgeable people willing to share their time and knowledge with others. Hopefully, in the future, I can do the same.

Thanks again, SunGlobes.