Summer coolant temp?

[Zooguy]

1999 LC 2UZ-FE 173k miles 6600lbs 33s

I have an UltagaugeII so I can see actual coolant temps instead of the stock gauge.

Most of the time it runs at 188-194*f maybe up to 205*f if I try to go 85mph up a hill.

Over the winter I put a new radiator in it and heater-ts been running good. Yesterday when driving on the highway at about 65-70mph my alarm goes off in the ultragauge and i see my temp was 217*f so I slow down to 60mph and it starts cooling down slowly. (Alarm set at 215*f)
The air temp outside was 93*F and very humid. Would y'all say that is normal?

What temperature do y'all's run at in the summer? How hot would y'all say is too hot?

 

[bobcatag2006]

I check mine on the Bluetooth app I have. I hit 194-198 in summer in central Texas. Yesterday it got to 100 and I was driving all day on a gravel trail run and then 2 hours home on 70-75 mph. Never got above 197 yesterday.

 

[94SRUNNER]

I run 184-190 depend on driving conditions.

How is your thermostat?

 

[2001LC]

With the: 98-02: 184F to 187F monumentally touching 190F in worst condition. This with both A/Cs on, stop & go HWY traffic, up and down Montanans passes along mild off road with OAT running 87f to 100F. Well tune, no vacuum leaks, fuel cleaners like 44K used, new radiator, thermostat & cap. All radiator (engine, condenser, transmission) fins cleaned of debris, w/350K+ miles on the clock.

Edit 8/16/22:
03-07 seems 184-187F w/OAT<70f. In summer heat on sunny day w/OAT of much above 70: 194f to 197F.

 

[94SRUNNER]

06-07 Still gathering logs, but seems 184-187F w/OAT<70f. In summer heat on sunny day w/OAT of 91F: 187f to 194F up to 197F. VVT engine has different fan, fan clutch, throttle, intake manifold along with VVT.

This lines up nicely with my observations of my 06' over the last several years.

 

[OEMGUY0720]

This is at 8% humidity and 101°F outside temperature.
Highest I got was 203°F on a long stretch of mild uphill pass at 70mph, went easy on gas and stayed at 65 and temp dropped at 199°F. 253k miles on the radiator (original still I think). Oem Thermostat, TB, WP (aisin), oem coolant was replaced 8k+ miles ago.

 

[94SRUNNER]

This is at 8% humidity and 101°F outside temperature.
Highest I got was 203°F on a long stretch of mild uphill pass at 70mph, went easy on gas and stayed at 65 and temp dropped at 199°F. 253k miles on the radiator (original still I think). TB, WP (aisin), oem coolant was replaced 8k+ miles ago.

Curious what the status of your thermostat and fan clutch is?

 

[87warrior]

My '99 runs at 194-197°F in the summer and it stays at 194°F in the winter. It used to run at 187°F, but I suspect the Toyota thermostat I installed during my last timing belt was a 195°F.

 

[OEMGUY0720]

Curious what the status of your thermostat and fan clutch is?

Forgot to mention during the same time I did the TB, I also replaced the thermostat and fan clutch, upper and lower radiator hoses. Motor oil btw is 8100 motul.

 

[Live to Ski]

View attachment 2703270
This is at 8% humidity and 101°F outside temperature.
Highest I got was 203°F on a long stretch of mild uphill pass at 70mph, went easy on gas and stayed at 65 and temp dropped at 199°F. 253k miles on the radiator (original still I think). Oem Thermostat, TB, WP (aisin), oem coolant was replaced 8k+ miles ago.

What monitoring system are you using?

 

[OEMGUY0720]

What monitoring system are you using?

The App is called OBD Fusion
OBD Fusion - https://apps.apple.com/us/app/obd-fusion/id650684932)

The obd dongle is called Tonwon: Amazon product ASIN B06XTDFDPK

 

[DickB]

In my 01 LX I run 185-190 during the winter and the highest i've seen during the summer is 205 (that's when its 115 outside on a sunny day stopped in traffic on the highway) but I'm usually around 195-200.

 

[riffman12]

1999 LC 2UZ-FE 173k miles 6600lbs 33s

I have an UltagaugeII so I can see actual coolant temps instead of the stock gauge.

Most of the time it runs at 188-194*f maybe up to 205*f if I try to go 85mph up a hill.

Over the winter I put a new radiator in it and heater-ts been running good. Yesterday when driving on the highway at about 65-70mph my alarm goes off in the ultragauge and i see my temp was 217*f so I slow down to 60mph and it starts cooling down slowly. (Alarm set at 215*f)
The air temp outside was 93*F and very humid. Would y'all say that is normal?

What temperature do y'all's run at in the summer? How hot would y'all say is too hot?

Touching low 200s is fine in hot weather / big climbs but I would be concerned if I saw 217.

The fact that it cooled down when you slowed down most likely says the fan clutch is doing it's job

If it's at speed I would look at thermostat, radiator, gunk in the system etc.

 

[Zooguy]

What temp is the stock OE THERMOSTAT set to?

 

[94SRUNNER]

What temp is the stock OE THERMOSTAT set to?

82*C/179.6*F

 

[caslim]

Mine averages 200, with as high as 214 in the heat going up hill with a trailer. I'm suspecting the fan clutch as well. Going to replace that and the thermostat and see if it makes a difference. Thermostat was last changed in 2017 with a timing belt and water pump. Has a new radiator as well.

 

[Zooguy]

Mine averages 200, with as high as 214 in the heat going up hill with a trailer. I'm suspecting the fan clutch as well. Going to replace that and the thermostat and see if it makes a difference. Thermostat was last changed in 2017 with a timing belt and water pump. Has a new radiator as well

I've replaced the fan clutch with that blue one I forget the brand. It has a radiator that is less than 6 months old the water pump was replaced with the timing belt about a year ago. But I might go ahead and put a new thermostat in it.

 

[Brandon Ryder]

Just got my scanguage ii for this trip from CO to CA and back hauling a trailer. Outside temps averaged over 100. With an empty trailer, and climbing many hills, the engine temp often reached up to 208, but on the way back with a full trailer hauling max load( around 6k lbs), outside temp at 104 and climbing a grade, engine temp went to 215 and worst of all, trans temp went to 220. Alarmed and unable to help by downshifting, i pulled to the side of the road. I did not shut off the engine as that is how you destroy an engine that is hot. But with such high temps and the asphalt no doubt over 160 degrees, the engine and trans wouldn't cool below 215 and 222 respectively. Every attempt to move even a few feet shot trans temps up to 235.
Desperate and in a dangerous situation, i shifted the tcase into low and the trans into low with overdrive off to keep the torque converter locked. We started moving and temps immediately started to lower. Eventually i got on the highway again controlling my shifts to manage temps. Once it cooled enough i pulled over and shifted back into high and was on my way.

My main concern was the trans. The engine stayed at over 200 most the day but i controlled engine temps by driving slow and keeping the load relatively low. The trans i managed by keeping torque converter locked using od off and controlling my gear/speed. Trans only gets to 200+ now when climbing steep grades in high heat. Now when i anticipate that i pull over and use low range to make the grade. Max speed 25mph doing that but temps stay under control.

I popped my oem radiator doing the same trip last year but in the winter. I didn't have the scanguage then. I bet if i didn't have it this trip, i would have burned the trans at least.

I have a moshimoto all aluminum radiator replaced a few months ago, fresh Toyota red coolant, new heater Tees and hoses, new water pump about 30k ago. The only thing i haven't relaplaced is the fan clutch but that's next. Temps typically drop pretty quick though once heading down hill.

That scanguage saved my trans im sure. If you tow, you need one.

Btw driving with overdrive off really shoots those trans temps up high even when not climbing. Without a trailer its typically been fine.

Buy a scanguage!

 

[94SRUNNER]

Just got my scanguage ii for this trip from CO to CA and back hauling a trailer. Outside temps averaged over 100. With an empty trailer, and climbing many hills, the engine temp often reached up to 208, but on the way back with a full trailer hauling max load( around 6k lbs), outside temp at 104 and climbing a grade, engine temp went to 215 and worst of all, trans temp went to 220. Alarmed and unable to help by downshifting, i pulled to the side of the road. I did not shut off the engine as that is how you destroy an engine that is hot. But with such high temps and the asphalt no doubt over 160 degrees, the engine and trans wouldn't cool below 215 and 222 respectively. Every attempt to move even a few feet shot trans temps up to 235.
Desperate and in a dangerous situation, i shifted the tcase into low and the trans into low with overdrive off to keep the torque converter locked. We started moving and temps immediately started to lower. Eventually i got on the highway again controlling my shifts to manage temps. Once it cooled enough i pulled over and shifted back into high and was on my way.

My main concern was the trans. The engine stayed at over 200 most the day but i controlled engine temps by driving slow and keeping the load relatively low. The trans i managed by keeping torque converter locked using od off and controlling my gear/speed. Trans only gets to 200+ now when climbing steep grades in high heat. Now when i anticipate that i pull over and use low range to make the grade. Max speed 25mph doing that but temps stay under control.

I popped my oem radiator doing the same trip last year but in the winter. I didn't have the scanguage then. I bet if i didn't have it this trip, i would have burned the trans at least.

I have a moshimoto all aluminum radiator replaced a few months ago, fresh Toyota red coolant, new heater Tees and hoses, new water pump about 30k ago. The only thing i haven't relaplaced is the fan clutch but that's next. Temps typically drop pretty quick though once heading down hill.

That scanguage saved my trans im sure. If you tow, you need one.

Btw driving with overdrive off really shoots those trans temps up high even when not climbing. Without a trailer its typically been fine.

Buy a scanguage!

Did you replace you thermostat? I don’t see that mentioned?

 

[Brandon Ryder]

Did you replace you thermostat? I don’t see that mentioned?

It was replaced with timing belt and water pump. Factory tstat. And before anyone asks, the giggle valve was correctly oriented. I forgot if it's up or down but i followed all the threads on mud when i did it.