Temperature "too perfect" (1 Viewer)

jvazquez53

El Tractor
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I have been driving this "new truck for about two weeks now and I have observed that the temperature goes to the 1/2 mark rather quick. It does not go higher or lower it works too perfect for me, if it works why not break it?. So I went and dug in and found that there was no thermostat. I wondered why it was removed, I've been told that fuel injected vehicles do need a thermostat. My defunct 60 ran without one with no problems, but that's another story. This truck have an extra electric fan, I know this because my other 80 is almost pristine and don't have one, I use my gray 80 for comparing parts. Tomorrow I'll see how it behaves with the installed thermostat.

Next: -Power windows, and windshield washer (leaks)

- Replace axle oil with Royal Purple Gear Oil
- Replace Transmission fluid with Amsoil
- Detailing (wife's idea)
- ARB bumper (A MUST!)
 
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NLXTACY

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Not having a thermostat is pretty weird in an 80. May want to consider the coolant temp gauge mod or perhaps use a secondary gauge. As far as the extra fan, that is more than likely the JDM fan which is used for A/C equipped NON-USA trucks.
 
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Not to rain on your parade vazquez53. I have an experience with a thermostat stuck open on a Honda. Driving on the freeway on a cool day actually over cools the engine. Making the ECU think the engine has just started and put more fuel in it. My mileage jump up 30% after I put a new thermostat in.

Also the engine are designed to be operated in an optimum temperature range for best fuel efficiency and wear characteristics.

I would suggest to get an aftermarket engine temp gauge like NLXTACY said just in case.
 
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Even in hot countries (like Zambia) having no thermostat is a bad idea - my isuzu took ages to warm up properly on a long cruise, even at 40 degrees - until I thought to check the stat and realised that the "bush mechanic" didn't bother putting it back in - mistakenly thinking it would run better that way
 
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Strange,

What do you mean by rather quick. It should be the opposite w/o the thermostat...It should take a while for the truck to warm up ???
 

jvazquez53

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Strange,

What do you mean by rather quick. It should be the opposite w/o the thermostat...It should take a while for the truck to warm up ???
Quick to me was about 5-10 minutes in stop and go traffic which is the norm here, I'm using my other 80 for a baseline. I know the other runs fine, all I've done the gray ("La Tractorcita") is oil changes and add fuel, very reliable (it's my daughter's truck). Now that I installed a new thermostat, I'll see how the truck works.
 

jvazquez53

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Not having a thermostat is pretty weird in an 80. May want to consider the coolant temp gauge mod or perhaps use a secondary gauge. As far as the extra fan, that is more than likely the JDM fan which is used for A/C equipped NON-USA trucks.
The extra fan looks like aftermarket, not OEM at all. I'm not going to take it out, that extra cooling is not bad.
 

Cruiserdrew

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I assume we are talking the 3FE in the 92.

Anyway, there are 2 temp sensors, one just under the thermostat that runs the gauge and one I think in the head, that supplies the info to the EFI.

It does like to run in a fairly narrow temp range, so putting in the thermostat is a very smart idea. It should warm up the motor quicker but the sensor under the t-stat slower with the thermostat back in place.
 

e9999

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Additional electric fans are great for better cooling when you're crawling on the rocks or in traffic, but this comes at the expense of fuel economy, of course.
I don't know/recall how much power / mpg those will cost, but it is probably not that far -when running- from what is used by the mechanical fan, not an insignificant amount.
 
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My current 3fe warms up within 1.5 miles of start-up to normal operating temp (2-3 minutes) with a well functioning thermostat/o-ring/gasket in below 32f temps.

I had a not so well functioning system on a 3fe (deteriorated & nonseated o-ring) basically never warm up in the winter even on drives of hundreds of miles. It also took a long time to warm up in the summer and really never operated at optimal and or steady temps on 90+ degree days in this condition either.
 

jvazquez53

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I drove to work today, the tuck behaved fine, never passed the 1/2 mark in the temp gauge. However I believed that when the thermostat is closed and the engine is running, the radiator upper hose should feel stiff, is this is correct? Could the thermostat is not seated properly and coolant is being bypassed? The one on my truck never felt stiff, the electric fan is always on and supplements the OEM fan. Like I said, the truck performed fine, even hit a traffic jam.:confused:
 
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I think it would be hard for the thermostat to be not seated as the thermostat fits down in the base of the water outlet in the groove, the outlet gasket goes over that, and then the o-ring is installed. I use a thin film of blue gasket sealer on both sides of the outlet gasket (optional but I do not go w/o it), and snug it down.

The upper hose does feel stiff when hot. I would make sure: 1) stat is not upside down as it will bypass; 2) o-ring is installed/ seated and centered correctly in the top housing as it will bypass if not correct since it is a slotted thermostat; 3) check the rad cap to make sure it is functioning properly.

My temp gauge runs at half mark
 

jvazquez53

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I think it would be hard for the thermostat to be not seated as the thermostat fits down in the base of the water outlet in the groove, the outlet gasket goes over that, and then the o-ring is installed. I use a thin film of blue gasket sealer on both sides of the outlet gasket (optional but I do not go w/o it), and snug it down.

The upper hose does feel stiff when hot. I would make sure: 1) stat is not upside down as it will bypass; 2) o-ring is installed/ seated and centered correctly in the top housing as it will bypass if not correct since it is a slotted thermostat; 3) check the rad cap to make sure it is functioning properly.

My temp gauge runs at half mark
Here is a picture of the thermostat placement, I believe is where its supposed to be, the o-ring is not on the picture, but its installed. The gasket is fine, I used the gasket sealer was used also, no leaks. The radiator cap is new, I wen and used a 13 PSI just like my other Toyotas. My temp gauge runs at 1/2 mark also, the only thing that could be is that by using that extra fan, the temperature is kept on the lower side.:hmm:
Tstat.JPG
 
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Looks good/correct to me. Did you replace the o-ring when you replaced the thermostat ? Just wondering, those o-rings flatten and deform over time and should not be reused. If that does not seal you defeat the purpose of changing your thermostat...It just bypasses if not sealed...Makes a huge difference.
 

jvazquez53

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Looks good/correct to me. Did you replace the o-ring when you replaced the thermostat ? Just wondering, those o-rings flatten and deform over time and should not be reused. If that does not seal you defeat the purpose of changing your thermostat...It just bypasses if not sealed...Makes a huge difference.
I did used a new o-ring, still I'm going to take it apart one more time to make sure the o-ring is placed correctly.:wrench::wrench::beer::wrench::wrench:
 

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