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So my '14 GX was delivered from the dealership with an always-open (hot climate in Saudi Arabia.) However, the engine never reaches optimum temperature (never raises above 1/3 of the gauge) not to mention it takes more than 15+ minutes at idle to reach optimum operating temperature especially during the winter months. I tried to plead with the dealership, but they maintain thats how it was intended.
I picked up a thermostat from the states but i was wondering if anyone had the instructions on replacement. More specifically if it needed to air purged out of the system and the best method (bleeding screws, etc.)
I have a question about your use of the vehicle. Why are you idling the vehicle so long (15+ minutes)?
I would be concerned that starting the vehicle, but not driving the vehicle for so long is less than optimum as oil pressure and therefore oil distribution is a function of engine speed. Even in the relative cold of Northern Virginia there's no reason not to start driving immediately after starting as the transmission will limit upshifts to keep the RPMs higher until the engine is fully warmed. It should be only a matter of a few minutes and less than a mile before that happens.
Regards,
I use my remote start to warm up my GX every morning in the fall and winter months and even in the evening before I get in it after work. Very nice to get in to a warm vehicle rather hold an ice cold steering wheel and sit on an ice cold seat. In the summer I use my remote start to cool it off as well before I get in. I have done this on all of my vehicles since I've had remote start in my first vehicle in 94 and have yet to have an issue.
I use my remote start to warm up my GX every morning in the fall and winter months and even in the evening before I get in it after work. Very nice to get in to a warm vehicle rather hold an ice cold steering wheel and sit on an ice cold seat. In the summer I use my remote start to cool it off as well before I get in. I have done this on all of my vehicles since I've had remote start in my first vehicle in 94 and have yet to have an issue.
Hadn't considered that, Eppieguy ... thanks for the reminder. Our garage is conditioned space so our GX isn't much different than interior temperature and we don't face the discomforts you described. For vehicles in unconditioned garages and especially vehicles parked outside, remote start would be welcome ... especially since the HVAC can be left in the AUTO mode.
Regards,
in hot climates such as Saudi Arabia the engine coolant is going to be hot and close to operating temp when started. soon as you leave your air conditioned garage 5- 10 min in the heat the coolant will be hot. A common practice in hot climate countries is to actually remove the thermostat all together. I would advice not to swap it out if thats how it comes stock. at idle the engine runs rich which is a colder firing condition. instead of idling for 15 min drive it sooner but DO NOT red line the rpms or go above 3000-3500 rpms till the temp is near or at operating temp.
I have a question about your use of the vehicle. Why are you idling the vehicle so long (15+ minutes)?
I would be concerned that starting the vehicle, but not driving the vehicle for so long is less than optimum as oil pressure and therefore oil distribution is a function of engine speed. Even in the relative cold of Northern Virginia there's no reason not to start driving immediately after starting as the transmission will limit upshifts to keep the RPMs higher until the engine is fully warmed. It should be only a matter of a few minutes and less than a mile before that happens.
Regards,
SaniDel
I do not idle for that long, it was just to describe the current situation. Its almost as the T'stat is stuck in the open position (if one is even in there at all.) I honestly prefer the engine to reach operating temps more quickly and maintains it with a functioning T'stat.
Originally Posted by Eppieguy
I use my remote start to warm up my GX every morning in the fall and winter months and even in the evening before I get in it after work. Very nice to get in to a warm vehicle rather hold an ice cold steering wheel and sit on an ice cold seat. In the summer I use my remote start to cool it off as well before I get in. I have done this on all of my vehicles since I've had remote start in my first vehicle in 94 and have yet to have an issue.
Remote start was a good option till i learned how poorly the Lexus system was programmed. especially having to turn off and restart when approaching the car, just seemed very counter productive. It doesn't get that cold here (maybe mid 50's in the early AM) its just not fun to drive this car when its cold because the engine is trying to warm up for longer and we all know how this car loves to lurch forward at stop lights if the brakes are not jammed into the firewall.
Originally Posted by kornpeef
in hot climates such as Saudi Arabia the engine coolant is going to be hot and close to operating temp when started. soon as you leave your air conditioned garage 5- 10 min in the heat the coolant will be hot. A common practice in hot climate countries is to actually remove the thermostat all together. I would advice not to swap it out if thats how it comes stock. at idle the engine runs rich which is a colder firing condition. instead of idling for 15 min drive it sooner but DO NOT red line the rpms or go above 3000-3500 rpms till the temp is near or at operating temp.
Well, thats the case with the GS (imported from the states) and it warms up quick and keeps cool on the hottest of summer days (110F +.)
The GX on the other hand just takes wayyy too long to warm up. Even when it does the needle only goes one third of the way. I usually do just as you stated but since i have the T'stat in hand it doesn't hurt to pop it in and see how it works.
Anyone have a shop manual with some instructions i can follow? mostly if bleeding air out of the system requires a special procedure.
Anyone have a shop manual with some instructions i can follow? mostly if bleeding air out of the system requires a special procedure.
Maybe see if you can read a pdf of the cooling system portion of a GX460 or Toyota Tundra 4.6 liter V8 manual here https://techinfo.toyota.com/
A 2 hour subscription costs $15.00. Or post your question to tundrasolutions.com where many owners drive 4.6 liter Tundras and some of them are familiar with thermostat replacement. You could also try searching Youtube using "Tundra thermostat replacement" as your search words.
Your thermostat definately appears stuck open or missing altogether which is bad because the engine is overcooled even in a climate like Saudi Arabia or Phoenix, Arizona and that in turn causes excess fuel consumption and more carbon emissions that wear out / plug expensive emission control components prematurely.
Maybe see if you can read a pdf of the cooling system portion of a GX460 or Toyota Tundra 4.6 liter V8 manual here https://techinfo.toyota.com/
A 2 hour subscription costs $15.00. Or post your question to tundrasolutions.com where many owners drive 4.6 liter Tundras and some of them are familiar with thermostat replacement. You could also try searching Youtube using "Tundra thermostat replacement" as your search words.
Your thermostat definately appears stuck open or missing altogether which is bad because the engine is overcooled even in a climate like Saudi Arabia or Phoenix, Arizona and that in turn causes excess fuel consumption and more carbon emissions that wear out / plug expensive emission control components prematurely.
I did just that after reading your post and found the answer. Will be replacing my T'stat tomorrow. many thanks!
I recently bought a 2010 GX 460 with about 115k miles. The other day I noticed that the hood was very hot to the touch. This led me to pay closer attention to the temperature gauge and I have noticed that the gauge is reading about 1 line past the middle (Picture below). Taking a look with Torque (lite), it looks like the coolant temperature is "fine" running between ~190f and ~196f. I have seen it as high as ~201f. The temperature gauge never seems to move (forwards or backwards) once the engine is up to temperature.
The whole time I have been looking into this, I have had the "upper radiator cover" removed. I was under the impression that this was just useless plastic (like the engine cover), but further research shows that I could be wrong and that this cover could be vital for air flow, etc, etc. A quick test this morning, shows that the hood is no longer getting hot with the "upper radiator cover" installed. However, the temperature gauge is still going to its normal spot (past the middle) and I was not able to drive it long enough to figure out if the coolant temperature was lower.
When I bought the GX, it was leaking oil from the oil filter housing (quick and easy fix, no more leak) and it was low on coolant. I added more coolant and there is no apparent leak. I am going to take it to my local mechanic to have the oil and coolant changed and to see if they can track down any issues.
Does anyone know what the normal operating temperature is for the coolant/engine and has anyone experienced a similar issue? Also, any thoughts or suggestions on things to check would be greatly appreciated.
I recently bought a 2010 GX 460 with about 115k miles. The other day I noticed that the hood was very hot to the touch. This led me to pay closer attention to the temperature gauge and I have noticed that the gauge is reading about 1 line past the middle (Picture below). Taking a look with Torque (lite), it looks like the coolant temperature is "fine" running between ~190f and ~196f. I have seen it as high as ~201f. The temperature gauge never seems to move (forwards or backwards) once the engine is up to temperature.
The whole time I have been looking into this, I have had the "upper radiator cover" removed. I was under the impression that this was just useless plastic (like the engine cover), but further research shows that I could be wrong and that this cover could be vital for air flow, etc, etc. A quick test this morning, shows that the hood is no longer getting hot with the "upper radiator cover" installed. However, the temperature gauge is still going to its normal spot (past the middle) and I was not able to drive it long enough to figure out if the coolant temperature was lower.
When I bought the GX, it was leaking oil from the oil filter housing (quick and easy fix, no more leak) and it was low on coolant. I added more coolant and there is no apparent leak. I am going to take it to my local mechanic to have the oil and coolant changed and to see if they can track down any issues.
Does anyone know what the normal operating temperature is for the coolant/engine and has anyone experienced a similar issue? Also, any thoughts or suggestions on things to check would be greatly appreciated.
Thanks!
Yes ... the upper radiator cover is important ... forces airflow thru the radiator ... otherwise airflow will take the path of least resistance.
Thermostat is a 180-degree ... so normal operating temperature should cycle in the mid 180-degree range. You are not that far off ... high(er) ambient temperatures and engine load can push slightly higher. Yes, gauge is designed so "normal operating temperature" has the needle in 12 o'clock position.
Yes ... worth having things checked out. Given the age, cheap insurance to replace the radiator cap ... should maintain cooling system at 15-psi ... and if doing a coolant flush, I would replace the thermostat as well ... inexpensive part and is a quick change-out.
The temperatures you listed are normal operating temperatures. The 180 means it starts opening at 180 and fully opens when another 10-15F warmer. You will see hotter coolant when the ambient is higher. I own a few German Tiger tanks that run hotter than this, sometimes even up to the 230's and that is normal for those vehicles.
The temperatures you listed are normal operating temperatures. The 180 means it starts opening at 180 and fully opens when another 10-15F warmer. You will see hotter coolant when the ambient is higher. I own a few German Tiger tanks that run hotter than this, sometimes even up to the 230's and that is normal for those vehicles.
My GX460 consistently runs between 184-186 degrees ... as did my GX470 ... only (temporarily) jumps higher on hard acceleration, but never exceeds 192 degrees.
Engines typically run hottest when idling with A/C on in hot ambient (only the fan(s) move the air), that's when cars typically overheat.
Coolant operating temperature from the SM: Standard value Between 75 and 100°C (167 and 212°F) with warm engine so the values listed by the OP are perfectly within the range.
This happened to my 2011 GX460 just yesterday (237K). Ran codes on an Innova 6030P and P0125 came up: “Insufficient Coolant Temperature for Closed Loop Fuel Control”. I checked the coolant and it was low (I noticed a small leak from a radiator/hose connection). I topped it off and took it to my mechanic in the a.m. He used a better scan tool and came up with a failed thermostat. Apparently, this light combo comes up in Toyota/Lexus when, among other things, the thermostat isn’t working. When I told him I had topped it off, he reset the codes and everything has been normal.
A pretty specific incidence that set those lights on but it’s easy enough to check and eliminate.
01-01-15, 05:28 AM
Coolant Thermostat - Questions/Concerns/Problems
What thermostat to use?
