What is too hot? It's not going to boil over until something like 250° if your cooling system is holding pressure. I'd be interested in seeing what the temps are like on a brand new vehicle with a similar engine in the same conditions (idling with AC on in Phoenix in the summer).
High coolant temps
- Thread starter hammerheadfistpunch
- Start date
-
- Tags
- coolant
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
This is the question we need answered haha. Is 216F hot? if so, how hot? what is the maximum recommended coolant temperature of the 2UZ engine.... The truck is all stock with regards to cooling/engine performance, so if it can reach into the 216-220F range just idling in the Arizona heat, it must be within the operational limits...or so I would hope.
- Thread starter
- #43
As per a 3rd party conversion with one of the engineers that did the cooling system performance testing for the gx470. 215 is above normal, 220 is careful watching, 225-230 is take action.
From what I was told, they had to block a lot of the radiator off in high heat to get it up to danger temps.
The needle moves at 230 right up to high
I laugh only because you have no idea what is too hot but yet are convinced the temps you are seeing are unacceptable. I have no idea what the acceptable range for our trucks is, but have been seeing 190-217f towing our 4500lb 20ft travel trailer, AC blasting and going around 60-65mph in 65-85 degree temps. Tranny temps have crept up and over 200f a few times, but usually stay in the 180-190f range.
I remember towing our 3200lb pop up camper w/ the wife's Sienna and seeing over 200f a few times, but nothing crazy.
I have been thinking about checking the foam and maybe adding some shrouds around those areas for experimenting. I am using Torque PRO w/ an OBDII dongle.
I remember towing our 3200lb pop up camper w/ the wife's Sienna and seeing over 200f a few times, but nothing crazy.
I have been thinking about checking the foam and maybe adding some shrouds around those areas for experimenting. I am using Torque PRO w/ an OBDII dongle.
- Thread starter
- #45
Me?
Thank you for the updated information. So, 220F idling with the AC on is above normal. I guess I will start investigating the cooling system. I'll start with the thermostat and coolant then go from there. I did notice there is no foam around the radiator so I might add some after the thermostat change and I'll report my findings.
NMBruce
SILVER Star
I had a foam and after replacing the radiator, I no longer have foam, the temp gauge sits at the same place as before.
That's a good question. Lots of vehicles cruise around in the summertime at 200-205 on up. Where does the AC cutoff on these vehicles would be a good start to answering that question. If its right around the 220F mark like on an 80 series then you know the engineers at Toyota thought it perfectly acceptable for you to cruise around in comfort at anything under that temperature.
A common issue here on the mud forum. Lots of guys think that the temperature gauge should never move from 185 or 195. That's just not the case. My favorite is the " I was pulling my trailer over the pass, at altitude, and I was seeing 210,215,,220,etc" . Yeah, no $hit, its called a strain on the motor and it causes heat to build up, its normal. The original post of this thread is another good example. Running 205 over a pass, in the mountains, at altitude, in the mountains. Did I mention the part about being in the mountains ? That's normal temperature fluctuation.
Here's a few examples.
1) my 97 Land Cruiser has one of the cleanest and newest cooling systems going. Completely flushed, new rad, water pump, hoses, thermostat, etc. Driving around in Kansas on a 90* day it will run all day long at 185-190. Take the same Cruiser over the pass going out of Denver, in 50* weather, you are going to see 215* the whole way up. That's normal.
2) The old XJ Cherokee's are a great example of normal operating temperatures. 4.0 inline six, cast iron block and head, very high underhood temperatures are the norm. Driving around on a 90* you are going to see 205 - 215 on one that has a very well maintained cooling system. They will run like that for 300k miles and more with no problem.
- Thread starter
- #49
Seems unnecessary for this post and the referenced post to call out someone for asking. I'm very familiar with most things mechanical but broadly... The point of asking here is to politely ask for any specific insight on a specific system. It's not a reflection of lack of understanding to be concerned with temps based on experience on other vehicles but to simultaneously ask if the data is out of the curve for a specific vehicle. It does seem to be a forum constant for people to be condescending in a thread as opposed to providing answers to the question.
In this specific case we have the answer an no... These temps aren't normal. that people seem to have no problem running many miles with high temps doesn't mean that is a healthy system running normally.
"To hot" has been defined here to my complete satisfaction. In spite of the expert opinions on here and not because of them
Not saying I haven't and won't continue to get great help here but this "what a dumb question" attitude sure helps no one
Last edited:
I don't think anyone here is calling you dumb, certainly not me. I am however saying that you are working yourself up over no real issue. I'm also saying this is very common on more than one forum here on mud. You answered yourself with your own quote " that people seem to have no problem running many miles with high temps doesn't mean that is a healthy system running normally" then discounted the result by saying its not normal. I also gave you "specific insight on a specific system" with what I wrote below....
Which you discounted by saying .....
Essentially calling me out on a vehicle that I've kept solid numbers on for 4 years now. Also a vehicle with a much more substantial cooling system than the GX is running.
My point is, I'm not calling you an idiot by saying that your worrying about nothing. 205* is perfectly normal given the ...
1) size of the cooling system
2) work load put on the motor
3) altitude that you are driving
If you look a bit deeper into the problem you will see that you are not the only Colorado/Utah resident to complain of this issue across the board. In fact a good friend of mine called me earlier today on vacation in CO. Why, because his vehicle was getting hot driving around up there and the AC kept cutting out. He was perfectly fine when going across Kansas, but in Colorado things changed. Is that frustrating for him, yes. Is that normal, also yes.
I also don't remember seeing what gear you were running when you were going over the pass. It's easy to not think about it in a vehicle like the GX with plenty of spare power, but, if you drop down to 4th you will put a lot less strain (thereby less heat) on the motor then letting the trans decide for itself if it wants to be in 4th or 5th. If you haven't done it yet that would be worth a try next time your testing things out.
I totally understand the relationship between engine load and coolant temperature, and I am comfortable with the coolant temps in the 200F - 215F range while towing up a steep grade with the AC on and the ambient temperature in the 100-105F zone. My concern is while parked, with the AC on and no load, the temperatures continue to rise as long as the truck is stationary. 220F coolant temperature at idle with no load is too high, in my opinion and I'd like to see if I can remedy it.
- Thread starter
- #52
Its a nice sentiment that you seem to be willing to be civil about it, but the post you replied to and the tone in it were pretty patronizing.
I don't agree with your statement that my temps are perfectly normal just because other people also have high temps. Based on the information I gathered from the engineer that knows, no...215 is not a normal temp for towing a light load in moderate temps, even at elevation. In order for them to get the truck to even move the needle at 230 F during testing they had to block off most of the radiator and run it with a load in high ambients.
Yes loaded engines run hot, but thats why we have data. To know whats mildly deviating and whats outside the range of that deviation.
Im not trying to discount anything you said. I also have years of data on my vehicles, Im just giving you relevant info.
My initial run was with no trailer and very little load up to 9000 feet with cool ambient temps. 205 seems really hot for such conditions based on said data I've collected on past cars...which was my assertion initially, especially since my much heavier 80 does the same run 10 degrees cooler, even with a load or trailer.
217 while towing 3000 lbs to southern Utah half the GVWR, relatively mild ambient temps and relatively mild elevations is definitely not normal nor expected. (manually selected 3rd or 4th depending on the grade)
I have the info I came here for:
215 is abnormally hot
220 is careful watching
225-230 is danger zone
230+ take immediate action
I take issues with this "these people, right?" attitude you get on these forums sometimes.
"My favorite is the " I was pulling my trailer over the pass, at altitude, and I was seeing 210,215,,220,etc" . Yeah, no $hit, its called a strain on the motor and it causes heat to build up, its normal. The original post of this thread is another good example. Running 205 over a pass, in the mountains, at altitude, in the mountains. Did I mention the part about being in the mountains ? That's normal temperature fluctuation. "
1. No its not.
2. Its not hard to see the offense here.
Lets stick to the facts.
Jeez is there an emoji for panties in a bunch because this is where this thread has gone.
I find outside temps didn't matter as much in my past 80 that ran hot ever since changing out the radiator to a non Koyo one. Any grade would just bump the temps. I also think we stress out too much when we see these temps on our Ultra gauge or Scan Gauge. Heck sometimes ignorance can be bliss. If your system cools back down when action is taken or stress is removed then you don't have a clog that will leave you stranded. Can your system always run better sure!
I find outside temps didn't matter as much in my past 80 that ran hot ever since changing out the radiator to a non Koyo one. Any grade would just bump the temps. I also think we stress out too much when we see these temps on our Ultra gauge or Scan Gauge. Heck sometimes ignorance can be bliss. If your system cools back down when action is taken or stress is removed then you don't have a clog that will leave you stranded. Can your system always run better sure!
I too, used to have an 80 and as most people know, those are notorious for running hot. The hottest it ever got was 219F whenI was offroading here in AZ in the summer heat with the AC on. Idling in traffic and climbing hills, it rarely got over 205.
That is one thing I love about this GX is now I can off-road with the AC on which I rarely did in the 80. And as for idle I was able to do a Baja trip with my toddler sleeping in the car seat and make a stop at Coco's corner leaving the truck running with AC going for 20min and temps remained in check. So you may have some issues to look at with your system.
Thanks Mark. I suspect that the ambient temperatures have a lot to do with the high temperatures. When I observed the 220F coolant temperature, the outside air temperature was probably 108-110F and it was sitting in the Arizona sun. I've ordered a new serpentine belt, fan clutch, Toyota T-stat and I'm gonna flush the coolant. I'll report my findings.
I think with the parts you are planning to replace, especially the fan clutch, that you will now have peace of mind with this - even if the temps don't change much. But I'd wager the fan clutch will make a difference with the higher temps at idle.
I can relate to some of the prior posts because, as an ex-80 owner, I had become very paranoid about engine temps, which has generalized to all my cars. I bought a water-cooled Porsche about a year ago and have been monitoring the engine coolant temps carefully. That thing hits 210 all the time, even though the baseline cruising temp is about 186. I had been freaking out, and even installed an auxilliary radiator to get the temps down. Turns out the radiator fans aren't programmed to turn on at low speed until around 210, so the car is apparently designed to have the high temps. Point is, I think a lot of us 80 series guys have a bit of OCD with engine temps.
I can relate to some of the prior posts because, as an ex-80 owner, I had become very paranoid about engine temps, which has generalized to all my cars. I bought a water-cooled Porsche about a year ago and have been monitoring the engine coolant temps carefully. That thing hits 210 all the time, even though the baseline cruising temp is about 186. I had been freaking out, and even installed an auxilliary radiator to get the temps down. Turns out the radiator fans aren't programmed to turn on at low speed until around 210, so the car is apparently designed to have the high temps. Point is, I think a lot of us 80 series guys have a bit of OCD with engine temps.
Brad, yea you're probably correct. I want to compare the new FC to the existing one to see if the new one is stiffer. The FC I pulled off was "looser" than the stock one I had on my 80 prior to me swapping the clutch fluid to 10,000 cst. The belt was a "while I'm in there" item as it had began chirping a few months ago. I'm eager to see if there is a factory T-stat in there and if it's installed in the correct orientation. I'm not opposed to swapping the clutch fluid in the GX but from what I've read, this has yielded minimal gains. Once I modded the FC in my 80, I rarely saw over 204F, even in situations which used to cause temperatures to climb into the 210+ range.
- Thread starter
- #59
Part of the reason I asked here in the first place was that the radiator specialist shop I take my 80 to tells me that around the mid 2000's thermal engineering generally changed to favor higher temps for emissions reasons. The 80 wasn't designed around that idea and generally acts like anything older (pure cooling system capacity and operating efficiency). I didn't really buy the idea that any Toyota truck would be designed to run hotter temps, but I have noticed on the GX that the fun clutch doesn't engage until a reading of nearly 200 and then kicks off at 195.
As for AC effectiveness, isn't the electric kicker fan in charge of idle condenser air flow? It was my understanding that the electric fan was designed for that load specifically.
Not sure if that little electric fan is up to the task of handling 110 degree potential ambient temperatures with the relatively low CFM rating, hahaha. I even considered swapping it out for a large or higher CFM fan for the benefit of the AC in low speed situations.
