Normal coolant temps

[LittleCaesar]

Each auto and thermostat is different but years ago one car builder who worked for Eaton transmissions told me that the temp of the coolant should never exceed 15F degrees above what is stamped on the thermostat except in certain circumstances. In applying that so called insight to the 5vz, one shouldn't see more than 90.5C (195f) coolant temps on a continual basis.

Just my 2 cents.

 

[kolelt]

Why do you think that 212*F is ideal? There are many other engines that that each have their own designed operating range. My wife's Mini Cooper-S runs 225*F cruising and 185*F under power (two stage electrically controlled thermostat), as do many BMW's. There is not one 'ideal' temp for all engines.

Ideal is what Toyota designed the engine for - based on the 80*C/82*C stock thermostat, that is 176*F to 180*F at the inlet of the engine, which leads to ~185-190*F at the engine outlet (where the temp sensor for the engine is). The factory thermostat installed in the factory position gives 185-190*F coolant outlet temps.

If your 5vz-fe is running outside the factory designed range, it should be fixed. 210*F is still 'safe' but it isn't ideal. 3 nuts, flip the thermostat and re-install seems like a pretty easy fix...

-Charlie

Because almost 90% of people here said that they ran 200+ for years.

What facts do you have besides assuming it should not be at 212 or bellow 200.

Like I said according to my scangauge I run 190-208. Depending on the weather. Right now I was driving and it was 191 sometimes reached 198. On a hot humid summer day 205 with AC. Never once did I worry. Never once did the engine over heat or even the OEM gauge went up.

Long story short. There is nothing wrong with those temps.

 

[phattyduck]

Because almost 90% of people here said that they ran 200+ for years.

What facts do you have besides assuming it should not be at 212 or bellow 200.

Like I said according to my scangauge I run 190-208. Depending on the weather. Right now I was driving and it was 191 sometimes reached 198. On a hot humid summer day 205 with AC. Never once did I worry. Never once did the engine over heat or even the OEM gauge went up.

Long story short. There is nothing wrong with those temps.

Uh, what facts? The OEM thermostat is an 82*C = 180*F. In other words, it is designed to mix the coolant temp to 180*F at the inlet to the motor. A ~5-10*F rise through the motor is a normal number. Therefore, the outlet should be around 185-190*F. How is that not a fact?

The factory service manual states that the jiggle valve should be placed at 6 o'clock. How is that not a fact?

Many people have stated that when they corrected the jiggle valve position to the 6 o'clock position, their engine temps lowered back down to 185-190*F under all but the most demanding operating conditions. How is that not a fact? (though, yes, it is anecdotal)

No damage is not the same as correct. Just because no damage occurred doesn't mean that is be best way to operate the motor. There is a significant safety headroom in engine operating temperature of the motor, why eat up 20*F of that with a part installed incorrectly?

You may want to note that everybody with 'upside down' thermostats notes a very wide range of engine coolant temps. Everyone with a 'right side up' thermostat quotes a much narrower range. Coincidence? I don't think so...

-Charlie

 

[phattyduck]

I'm completely blown away by this thread. Everyone has normal Temps. 190-220 is normal operating temps. 212* ideally. To make sure heater is hot and ECU is going into closed loop correctly.

I kept my thermostat in the stock location. I run 195-210* and appreciate the heat.

Also note:

FSM says 176-203F is normal range

So no, 210* is not 'normal' on a 5vz. It may be normal on many other engines, just not in this case.

-Charlie

 

[catrains]

my 2016 T4R temp scan gauge runs at 186-190 deg f ... lower temp at slow speeds .. @ 80mph runs on the higher side. very solid IMO...

on my other vehicles GM the 180 F T stat operates at 185 deg f-200 deg f .. this is because it has electric fans . when stopped the temp will rise then the fans drop temp back down quickly.the electric fans I do not like because of this temp rise .when vehicle moves it drops to 185 deg f .. @90 mph drops down to 170 deg f .. on the GM belt driven fan engine the temp locks in at 195 deg f. some times up to 200 F on a very hot day. 195 F t stat.

any engine temp 15 deg f higher than T stat then there is a coolant system problem with a belt driven fan.

older vehicles that have this high temp issue it is most times a corroded and scale damaged system. the use of drinking water does this . distilled water must be used with the 50% and higher antifreeze .

some vehicles like a 5.7L hemi engine the coolant temp is 203 deg F ...I believe this high temp was designed so as to pass emission testing ..

Toyota dropped the engine temp on these new vehicles probably to get more HP out of the under sized engine.

 

[kolelt]

Also note:


So no, 210* is not 'normal' on a 5vz. It may be normal on many other engines, just not in this case.

-Charlie

According to TIS

Quote !

Thermostat is numbered according to the valve opening tem-
perature.

(A) Immerse
the thermostat in water and heat the water grad-
ually

(B) Check the valve opening temperature and valve lift.
Valve opening temperature:

80 - 84C ( 176-183F)
Valve lift: At 95c ( 203F): 8.5mm (0.335 in.) or more
If the valve opening temperature and valve lift are not within
specifications, replace the thermostat.

 

[kball]

Also note:


So no, 210* is not 'normal' on a 5vz. It may be normal on many other engines, just not in this case.

-Charlie

As the FSM says, up to 203 is normal. I think that pertains to everyday normal driving. It can and will go higher though. Climbing a long grade in 90 degree weather I've seen on my ultragauge, my temps go up to 215. I would say this is normal as well, for the driving conditions.

 

[mtbtim]

As the FSM says, up to 203 is normal. I think that pertains to everyday normal driving. It can and will go higher though. Climbing a long grade in 90 degree weather I've seen on my ultragauge, my temps go up to 215. I would say this is normal as well, for the driving conditions.

I've climbed some long grades in hot weather and the most I saw was 199. 215 sounds kind of high to me based off what I've seen with my rig. Like I said earlier in this thread, I was running between 188-192 for the most part before I replaced my radiator and thermostat. With the new thermostat, I was running 192-196. Now that I switched back the old thermostat, I'm back down to running at 188-192. I saw a thread on another forum where people were talking about the same thing I experienced when they replaced their thermostat and were now running at higher temps than before.

Have you checked your thermostat jiggle valve position and have you tested your fan clutch? It seems to me something isn't right that your engine coolant is getting that high.

 

[kball]

I've climbed some long grades in hot weather and the most I saw was 199. 215 sounds kind of high to me based off what I've seen with my rig. Like I said earlier in this thread, I was running between 188-192 for the most part before I replaced my radiator and thermostat. With the new thermostat, I was running 192-196. Now that I switched back the old thermostat, I'm back down to running at 188-192. I saw a thread on another forum where people were talking about the same thing I experienced when they replaced their thermostat and were now running at higher temps than before.

Have you checked your thermostat jiggle valve position and have you tested your fan clutch? It seems to me something isn't right that your engine coolant is getting that high.

I've replaced my water pump, thermo and rad when I did my timing belt. The jiggle is down. My fan clutch is probably original but I hear it every morning on start up and since I was running a steady 65-70mph up the grade I don't think the fan was very needed.

 

[JayRolla]

I've climbed some long grades in hot weather and the most I saw was 199. 215 sounds kind of high to me based off what I've seen with my rig. Like I said earlier in this thread, I was running between 188-192 for the most part before I replaced my radiator and thermostat. With the new thermostat, I was running 192-196. Now that I switched back the old thermostat, I'm back down to running at 188-192. I saw a thread on another forum where people were talking about the same thing I experienced when they replaced their thermostat and were now running at higher temps than before.

Have you checked your thermostat jiggle valve position and have you tested your fan clutch? It seems to me something isn't right that your engine coolant is getting that high.

You do realize under hood Temps, ambient temp, engine load, weight, grade will have affect on temp. It's winter so you should run a little cooler.

But if your under 194* than your motor is also out of temp spec. It's running to low. At least that's the logic when people say 200*+ is to high. Makes zero sense.

On 105* day climbing a grade loaded down I can see 210* this is perfectly normal. Especially with the trans heating up the coolant.

 

[ThorInc]

I saw temp above 200* when my jiggle valve was at 12. Flipped it to 6 (per FSM) and have never gone above 195-197* since. Works for me. Normal op temp range for me is below 190* now .

 

[mtbtim]

You do realize under hood Temps, ambient temp, engine load, weight, grade will have affect on temp. It's winter so you should run a little cooler.

But if your under 194* than your motor is also out of temp spec. It's running to low. At least that's the logic when people say 200*+ is to high. Makes zero sense.

On 105* day climbing a grade loaded down I can see 210* this is perfectly normal. Especially with the trans heating up the coolant.

Well, all I can say is I've never seen the temps you're experiencing in my rig. I have done several mountain biking/camping trips in the summer heat (90-100 degrees), I'm loaded down with lots of gear driving up long mountain passes and the highest I've seen is 199. When I saw 199, yes, my trans temps were up pretty high as well.

So, seeing your coolant temps hitting 210-215 might be normal for you and others but it's not normal for my engine. If I wanted to hit 210, I'd just flip my thermostat jiggle valve to the 12 o'clock position and then I'm sure 210 would be normal for me as well.

If a new 3rd Gen owner told me they were running that hot, I'd suggest they start investigating some things like thermostat jiggle valve position, fan clutch operation, etc. Even if you're driving at a fast speed, I'd still think a tired fan clutch not locking up could be the culprit of seeing higher coolant temps. When the fan clutch is bad, it will not be matching the speed of the engine and thus it will pull less air through the cooling fins of the radiator.

Anyway, if you're comfortable with the coolant temps you're seeing, that's all that matters.

 

[giovannie23]

when i first flipped my tstat i never ran above 193 during normal city driving
just days ago i started hitting 195
only when in idle, but when i start driving its back down to 191 or so
would you guys consider this normal?
or maybe signs of a fan clutch starting to go?
fan clutch passes all test and has a healthy roar
im not worried but just bothers me that im running 2 degrees hotter than usual

 

[kolelt]

Well, all I can say is I've never seen the temps you're experiencing in my rig. I have done several mountain biking/camping trips in the summer heat (90-100 degrees), I'm loaded down with lots of gear driving up long mountain passes and the highest I've seen is 199. When I saw 199, yes, my trans temps were up pretty high as well.

So, seeing your coolant temps hitting 210-215 might be normal for you and others but it's not normal for my engine. If I wanted to hit 210, I'd just flip my thermostat jiggle valve to the 12 o'clock position and then I'm sure 210 would be normal for me as well.

If a new 3rd Gen owner told me they were running that hot, I'd suggest they start investigating some things like thermostat jiggle valve position, fan clutch operation, etc. Even if you're driving at a fast speed, I'd still think a tired fan clutch not locking up could be the culprit of seeing higher coolant temps. When the fan clutch is bad, it will not be matching the speed of the engine and thus it will pull less air through the cooling fins of the radiator.

Anyway, if you're comfortable with the coolant temps you're seeing, that's all that matters.

The TIS said 203 F. let's stop creating threads that say the truck is broken when it's not. Your more then free to lower your engine temps. But can we agree that it's not broken at 210.

 

[mtbtim]

The TIS said 203 F. let's stop creating threads that say the truck is broken when it's not. Your more then free to lower your engine temps. But can we agree that it's not broken at 210.

Dude, this thread has lots of value. It seems you don't like it because guys like me and others that have commented are proof these engines can run cooler than you are currently. What you should be asking yourself is how other rigs with the same engine and same exact OEM parts for their cooling system are able to run much lower than you. It's threads like this that inspire people to investigate why they're running hotter than others and they find a fix like changing the position of the jiggle valve or replacing a tired fan clutch.

And, you're looking at the 203 value all wrong. I just used that page out the FSM to test the function of my old thermostat and newer thermostat. All the FSM is telling you is you should see the spring open 8.5mm from where it sits at a temperature of 203 degrees. The spring sticks out approximately 7mm from the body of the thermostat. When you hit 203, you take another measurement and the end of the spring should now be about 15.5mm away from the body. What I noticed with this test was my old thermostat was opening 2mm further than my new thermostat which is why I run 4 degrees cooler with my old thermostat. So, on that particular page, the FSM IS NOT telling us the normal operating temp of our rigs is 203.

Myself and others stand behind our opinion that if you're regularly running in the 200's while others like me never see the 200's, something is up and it's your choice whether you want to investigate further or just leave it as is.

So no, I absolutely don't agree with you that seeing 210 is fine and an acceptable cooling system temperature for our rigs.

 

[ThorInc]

Dude, this thread has lots of value. It seems you don't like it because guys like me and others that have commented are proof these engines can run cooler than you are currently. What you should be asking yourself is how other rigs with the same engine and same exact OEM parts for their cooling system are able to run much lower than you. It's threads like this that inspire people to investigate why they're running hotter than others and they find a fix like changing the position of the jiggle valve or replacing a tired fan clutch.

And, you're looking at the 203 value all wrong. I just used that page out the FSM to test the function of my old thermostat and newer thermostat. All the FSM is telling you is you should see the spring open 8.5mm from where it sits at a temperature of 203 degrees. The spring sticks out approximately 7mm from the body of the thermostat. When you hit 203, you take another measurement and the end of the spring should now be about 15.5mm away from the body. What I noticed with this test was my old thermostat was opening 2mm further than my new thermostat which is why I run 4 degrees cooler with my old thermostat. So, on that particular page, the FSM IS NOT telling us the normal operating temp of our rigs is 203.

Myself and others stand behind our opinion that if you're regularly running in the 200's while others like me never see the 200's, something is up and it's your choice whether you want to investigate further or just leave it as is.

So no, I absolutely don't agree with you that seeing 210 is fine and an acceptable cooling system temperature for our rigs.

I am with him^^^^^

 

[kolelt]

Dude, this thread has lots of value. It seems you don't like it because guys like me and others that have commented are proof these engines can run cooler than you are currently. What you should be asking yourself is how other rigs with the same engine and same exact OEM parts for their cooling system are able to run much lower than you. It's threads like this that inspire people to investigate why they're running hotter than others and they find a fix like changing the position of the jiggle valve or replacing a tired fan clutch.

And, you're looking at the 203 value all wrong. I just used that page out the FSM to test the function of my old thermostat and newer thermostat. All the FSM is telling you is you should see the spring open 8.5mm from where it sits at a temperature of 203 degrees. The spring sticks out approximately 7mm from the body of the thermostat. When you hit 203, you take another measurement and the end of the spring should now be about 15.5mm away from the body. What I noticed with this test was my old thermostat was opening 2mm further than my new thermostat which is why I run 4 degrees cooler with my old thermostat. So, on that particular page, the FSM IS NOT telling us the normal operating temp of our rigs is 203.

Myself and others stand behind our opinion that if you're regularly running in the 200's while others like me never see the 200's, something is up and it's your choice whether you want to investigate further or just leave it as is.

So no, I absolutely don't agree with you that seeing 210 is fine and an acceptable cooling system temperature for our rigs.

I understand. And please dont take it to the heart. But I guess running these temps for 5 years hasnt caused anything. Theres nothing wrong with few degress here or there.

I dont disagree with the jiggle handle position. What i am simply disagreeing, and this is just my opinion from experience. That if someone, some times sees a 205-208 temp shouldn't start ripping their engine apart.

Unless, someone states that there engine has overheated, or caused damage at those temps, then i strongly stand behind my opinion.

Again, i totally respect your words, sometimes its hard to show respect through words.

 

[mtbtim]

I understand. And please dont take it to the heart. But I guess running these temps for 5 years hasnt caused anything. Theres nothing wrong with few degress here or there.

I dont disagree with the jiggle handle position. What i am simply disagreeing, and this is just my opinion from experience. That if someone, some times sees a 205-208 temp shouldn't start ripping their engine apart.

Unless, someone states that there engine has overheated, or caused damage at those temps, then i strongly stand behind my opinion.

Again, i totally respect your words, sometimes its hard to show respect through words.

I hear what you're saying. But the fact you're not actually overheating doesn't mean some negative effects are happening to your engine. Maybe running 10 degrees hotter for years will cause a premature failure of a head gasket. I don't know. I'm just of the opinion that if you know you can run cooler, why not do some investigating. You don't have to tear apart an engine to figure this out. I cover this in one of the videos I made. Some people have a partially clogged radiator. Some have a bad radiator cap. Some have the thermostat jiggle valve in the wrong position. Some didn't properly burp their cooling system after they drained it. Some have a failing fan clutch. These are all easy things to replace and aren't ridiculously expensive. The one that's hard and potentially expensive is if you have a bad head gasket.

Anyway, Happy Trails Brother.

 

[Herculean T4R]

I replaced my t-stat today. Jiggle valve on old t-stat was at 12 o'clock position. My coolant temp dropped by about 10 deg F. I'm running 188 - 192 deg F now, whereas with old t-stat I was 199 - 205 deg F. Timmy's video was very helpful.

 

[mtbtim]

I replaced my t-stat today. Jiggle valve on old t-stat was at 12 o'clock position. My coolant temp dropped by about 10 deg F. I'm running 188 - 192 deg F now, whereas with old t-stat I was 199 - 205 deg F. Timmy's video was very helpful.

We have another believer that the jiggle valve position definitely makes a difference in the coolant temps. Glad the video helped you out.