I am stumped-Eng Temp issues

[KainDrag]

yea its all about your nipple valve orientation on your stat.
if its at 12 o clock your temps will be at 205+
if its at the 6 o clock your temps will be 190

I set mine at 12 o clock cause i followed the tacoma video and I see 210 - 212.
With a minnesota winter coming Im going to leave it there and see how it does.
when I changed my thermostat it was already at the 12 and its been like that for the last 100k miles.

 

[Jhelms]

Edit: No idea how I got NJ, well if you are in socal - away from the ocean a bit, then just like AZ, our rads and condensers get filled with dirt! No need to use coil cleaner, spray some water and let it soak. Then blast it out with a pressure washer. Will look like brown mud flowing out of both.

Would be much better if you take out your radiator and clean it in the same manner.

You will be surprised the crap that will get flushed out. If you start to see lower temps then you are set. If not, check the orientation of the thermostat.

Just a note, but even in the extreme heat in Az, I see 190 - 194ish.

 

[MandAtaco]

yea its all about your nipple valve orientation on your stat.
if its at 12 o clock your temps will be at 205+
if its at the 6 o clock your temps will be 190

I set mine at 12 o clock cause i followed the tacoma video and I see 210 - 212.
With a minnesota winter coming Im going to leave it there and see how it does.
when I changed my thermostat it was already at the 12 and its been like that for the last 100k miles.

I thought the valve was simply for bleeding air purposes, I've never heard anyone "setting the temp of the T-stat" by clocking the valve. That's a new one to me.

 

[KainDrag]

I thought the valve was simply for bleeding air purposes, I've never heard anyone "setting the temp of the T-stat" by clocking the valve. That's a new one to me.

It is but for some reason it also drops the temp 20 degrees

 

[Drcoffee]

Looking to understand this better. If you have an efficient radiator and the t-stat is on the water pump inlet, wont the t-stat stay closed if the incoming coolant is below 180*? In my mind, it would make more sense to have the t-stat on the outlet ejecting water as it reaches 180*. But if the inlet is staying closed, limiting flow into the engine, wont the engine run hotter? I mean, the water has to come in at at least 180* and then move through the engine. By the time it exits the engine, the coolant has to be near 210*.

Is there a way to move the t-stat to the outlet? Are there any other 3.4 engines designed differently, or other motors that share parts?

 

[KainDrag]

Looking to understand this better. If you have an efficient radiator and the t-stat is on the water pump inlet, wont the t-stat stay closed if the incoming coolant is below 180*? In my mind, it would make more sense to have the t-stat on the outlet ejecting water as it reaches 180*. But if the inlet is staying closed, limiting flow into the engine, wont the engine run hotter? I mean, the water has to come in at at least 180* and then move through the engine. By the time it exits the engine, the coolant has to be near 210*.



Is there a way to move the t-stat to the outlet? Are there any other 3.4 engines designed differently, or other motors that share parts?

The same engine in the Tacoma but valve oriented at 12 o clock

 

[AZPartsGuy]

Looking to understand this better. If you have an efficient radiator and the t-stat is on the water pump inlet, wont the t-stat stay closed if the incoming coolant is below 180*? In my mind, it would make more sense to have the t-stat on the outlet ejecting water as it reaches 180*. But if the inlet is staying closed, limiting flow into the engine, wont the engine run hotter? I mean, the water has to come in at at least 180* and then move through the engine. By the time it exits the engine, the coolant has to be near 210*.

Is there a way to move the t-stat to the outlet? Are there any other 3.4 engines designed differently, or other motors that share parts?

As far as I am aware, there is coolant running through the engine the entire time. All the thermostat does is allow MORE coolant to enter the passageways. We also cannot forget that our motor oil is doing a big job of keeping the engine temperature down too.

The vehicle will operate just fine between the ranges stated by the other members here, but that doesn't mean that being above or below to a certain extent is going to cause an issue. If you are seeing temps above 210-220 that is when there would be some concern.

Toyota designed the t-stat location for reasons we're probably not privy to, it should really be kept that way. One would be better off swapping the radiator for a bigger one and moving more air through the fins with electric fans, but that's probably not going to do anything but give warm fuzzies to the driver. I am not an expert, though. Someone go try it and post a picture tutorial!

 

[Drcoffee]

My radiator is a dual core and I am fairly certain that the radiator is more than efficient. Even after a 4 hour drive, the lower radiator is only warm, not hot. I believe its the matter of the t-stat opening and at what temperature. I will probably go back to oem the next time the truck is home.

 

[Drcoffee]

WTF! I pulled out the fail-safe thermostat and installed a new toyota oem t-stat and my temp is now 86.8* down from 208*

Another affect I was curious about was the pressure in the upper radiator hose. As long as I have owned this truck (4 years with aftermarket t-stat), the upper hose is pressurized and hard to squeeze. Now with the oem t-stat installed the upper and lower hose feel less pressurized.

The only thing I can imagine that is taking place, is the size of the heat sink on the t-stat for the oem unit is heavier and reacts slower to inflows of cooled water, resisting the tendancy to close too quickly as coolant passes by.

 

[LittleCaesar]

I always use OEM t-stats. No guesswork. I take it the temp is supposed 186.8F.