Normal coolant temps

[4Runner4TW]

I'm consistently at 204-207. Which browsing this thread it looks like its high....

I had my Timing job done 85K ago at Right Toyota in Scottsdale. I guess its time to take it in again but to my new mechanic. I wonder if I caused any damage to the motor having it run that much hotter over the course of 4.5 years...

 

[LittleCaesar]

I tried the Lisle funnel to burp the system again and no change to my coolant temps. I ran the engine for 15 minutes at operating temperature with both heaters on full blast. I even ran the engine at around 1500 rpms for at least 5 or the 15 minutes. I was watching the funnel from inside the truck and I could see bubbles coming up. When no more bubbles were coming up, i took it for a test drive and I'm still running around 192-196. Pretty frustrating since I was actually running cooler before all the work. It's still my theory that the new thermostat spring being new doesn't open quite as far as the old one.

I'm sick of wondering if the new thermostat is the culprit so I'm going to drain my coolant into a clean bucket, put my old thermostat back in (luckily I kept it) and see if my theory is correct. If this doesn't do it, it might be the Aisin fan clutch not working as good as the OEM one I replaced.

Dang Tim I thought that would have fixed the increased reading in the temps.

Post pics of the two thermostats side by side.

Maybe the Aisin clutch just can't moved as much air. I compared the new Aisin one and my old one back years ago and they looked identical, even up to the spring size and fin count.

 

[mtbtim]

Dang Tim I thought that would have fixed the increased reading in the temps.

Post pics of the two thermostats side by side.

Maybe the Aisin clutch just can't moved as much air. I compared the new Aisin one and my old one back years ago and they looked identical, even up to the spring size and fin count.

I tested the two thermostats side by side in a pot of hot water, and the old thermostat was opened 2mm more than the new one at the same temperature. After installing the old thermostat and burping the system with the Lisle funnel, my temps are back down between 188-192 for the most part. I did see 194 on a test drive afterward, but since the work I did replacing the radiator and thermostat, I haven't seen 188 in a long time while driving. So, I was running 190-196 most of the time with the newer thermostat and I'm now running 188-194 with the older thermostat. So, I dropped a couple degrees.

Was it worth doing? I guess so, and maybe I'll see even a bigger difference when the summer rolls around and I do some mountain biking trips. With the newer thermostat, I remember seeing 199 degrees going up a grade on a pretty hot day. The fact that the older thermostat opens up easier as the temperature climbs will hopefully keep my temps in the low to mid 190's all the time. I reckon I'll find out this summer.

 

[LittleCaesar]

Wow. It is pretty sad when not even the OEM parts are as good as what is put in at the factory. As the old addege goes I guess, size does matter.

I hope you enjoy the funnel; I haven't found a better way to expel air from a cooling system doing shadetree repair.

 

[mtbtim]

Wow. It is pretty sad when not even the OEM parts are as good as what is put in at the factory. As the old addege goes I guess, size does matter.

I hope you enjoy the funnel; I haven't found a better way to expel air from a cooling system doing shadetree repair.

Well, my theory is this. Springs fatigue over time. It would make sense after thousands of cycles of opening and closing that the spring gets a little tired and will open farther because of it. I sort of think there was nothing wrong with the new thermostat. It just has a brand new, unbroken in spring.

I think everything would have been fine the way it was on my truck but it did bother me I was running hotter than I originally was before the parts replacements.

 

[jgue467]

I'm consistently at 204-207. Which browsing this thread it looks like its high....

I had my Timing job done 85K ago at Right Toyota in Scottsdale. I...

I wonder if they put the jiggle valve on upside down? :cowboy:

 

[kolelt]

Im about to swap over to a 170* thermostat and new radiator. Im usually at 195-197. I see 200 in city traffic on hot days. Try adding a bottle of redline water wetter, supposed to help with temps.

That's like normal. I don't understand why you guys like freak out about 190-208 temps ?

 

[mtbtim]

That's like normal. I don't understand why you guys like freak out about 190-208 temps ?

Because maybe we're slightly neurotic.

 

[mtbtim]

I'm consistently at 204-207. Which browsing this thread it looks like its high....

I had my Timing job done 85K ago at Right Toyota in Scottsdale. I guess its time to take it in again but to my new mechanic. I wonder if I caused any damage to the motor having it run that much hotter over the course of 4.5 years...

Like [MENTION=75316]jgue467[/MENTION] said, I bet your jiggle valve is at the 12 0'clock position. Just drain your coolant into a clean bucket, remove the lower radiator hose, remove the (3) 12mm nuts that hold the thermostat housing neck on, remove the neck and see what position your jiggle valve is at. You'll most likely see it at the 12 position so just pull it out (might take a little tug), and reinstall it with the jiggle valve at 6 position (pointing towards the ground). You will see your temps drop around 10 degrees and basically be where I was before I decided to put my old thermostat back in.

Btw, the torque spec for the (3) 12mm nuts is 14 ft-lbf.

 

[Nottoday]

I'm consistently at 204-207. Which browsing this thread it looks like its high....

I had my Timing job done 85K ago at Right Toyota in Scottsdale. I guess its time to take it in again but to my new mechanic. I wonder if I caused any damage to the motor having it run that much hotter over the course of 4.5 years...

That's what I run at also.

The engine seems to run very smoothly at that temp. I run a quality synthetic oil that can take that heat in stride.

 

[Herculean T4R]

Mine runs between 199 to 205. I will replace my tstat this summer.

 

[kolelt]

No but seriously. No offense to you guys. By all means change your thermostat and the whole nine yards. I run 192-198. Hot/humid summer day with AC on. Gets up to 205 according to scangauge.

Not once did I worry. Not once did the gauge handle went up.

99% of people here have these numbers. And there's simply nothing to worry. Just my opinion.

 

[mtbtim]

No but seriously. No offense to you guys. By all means change your thermostat and the whole nine yards. I run 192-198. Hot/humid summer day with AC on. Gets up to 205 according to scangauge.

Not once did I worry. Not once did the gauge handle went up.

99% of people here have these numbers. And there's simply nothing to worry. Just my opinion.

You're probably right and guys like me are worrying about nothing. I just got used to seeing certain temps when driving and it kind of pissed me off when I was actually running hotter with a brand new radiator, brand new thermostat and brand new fan clutch. At least I was able to prove my theory that the new thermostat was the culprit for my slight rise in coolant temps. Now that I have my old thermostat in, I'll just leave it in there until it's time to renew the coolant again. But who knows, maybe I'll just leave it in there for good.

 

[kolelt]

You're probably right and guys like me are worrying about nothing. I just got used to seeing certain temps when driving and it kind of pissed me off when I was actually running hotter with a brand new radiator, brand new thermostat and brand new fan clutch. At least I was able to prove my theory that the new thermostat was the culprit for my slight rise in coolant temps. Now that I have my old thermostat in, I'll just leave it in there until it's time to renew the coolant again. But who knows, maybe I'll just leave it in there for good.

Me to. I always over analyze things on my truck.

 

[LittleCaesar]

Well, my theory is this. Springs fatigue over time. It would make sense after thousands of cycles of opening and closing that the spring gets a little tired and will open farther because of it. I sort of think there was nothing wrong with the new thermostat. It just has a brand new, unbroken in spring.

I think everything would have been fine the way it was on my truck but it did bother me I was running hotter than I originally was before the parts replacements.

Cooler to a point is better in my book as well.

This piques my curiosity. Next time I am in the yard for parts I'll try and find a 5vz with hopefully the originally tstat in it.

 

[JayRolla]

That's like normal. I don't understand why you guys like freak out about 190-208 temps ?

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.

 

[kolelt]

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.

My point is, i can see how someone new can see this thread and freak out "over nothing".

cooler is better, but more then half of the people ran their truck for years in the 190-210 temps. Till they find a thread like this.

Like i said, by all means its your truck so you are free to do what you want. Just my opinion

 

[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.

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

 

[JayRolla]

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

Every car I have ever owned in 16+ years has ran between 195-210* depending on airflow and outside ambient temp. All these cars are rated for 195*. Im saying there is not issue with your car running that temp. 230* is overheating.

 

[phattyduck]

Every car I have ever owned in 16+ years has ran between 195-210* depending on airflow and outside ambient temp. All these cars are rated for 195*. Im saying there is not issue with your car running that temp. 230* is overheating.

Oddly enough, my experience is the opposite. All my cars have run 185-190*F under normal driving circumstances (moving vehicle), with the fans coming on at either 195*F (radiator outlet temp on the Camrys) or 205*F (engine coolant temp on the WRX and Outback XT).

And yes, all of those vehicle run the thermostat jiggle valve in the 12 o'clock position. The 5vz is an odd duck in that regard.

-Charlie