What's the normal range for 1GR temperatures.

I'm wheeling a lot this year and getting a ton of mud on my radiator. I wash it out at home but on the trail sometimes I'm seeing Temps on my scan gauge around 225 f. On the road I'm under 200 for but what is the safest operating range of the 1GR? What's the max it can run for an extended period without blowing the gasket?

 

Anything under the red H. Just kidding. Out of curiosity, how high does your dash needle go up to when its at 225? Ive never noticed mine go above half way.

 

The gauge is a dummy. By that I mean it didn't even move at 225 f. I would guess that above 230 for it probably moves pretty rapidly to red. Our coolant in Canada, which is a 55/45 blend of more coolant than water, boils at about 270 f with the stock radiator cap. That I know. I would expect red on the gauge to be somewhere around 250 f.

 

On my ultra gauge highest I've ever seen on my 15 4.0 is 190 and that's under load then it drops right back down to 185

 

That was my truck before I started wheeling and a few years of hard knocks lol

 

Normal range is 190-195*F. 200-205*F is acceptable. Anything over that and you are approaching temps which can degrade the life of gaskets, seals, and even your transmission. You are also potentially reaching boiling point of other fluids.

If I was you I would attempt to do a 20/80 or even a 10/90 mix of coolant/water. Water is capable of better cooling than coolant is and the coolant only serves as an anti boiling/ anti rusting/ lubricating agent in the radiator. So not a whole lot is needed to keep your passages from rusting.

Next time I do a coolant service to my truck you can bet that is the route I'll be going on mine.

 

I can't go that route. I live in Canada lol.

 

When towing uphill my MY13 6MT doesn't break 196*. Typically the truck runs around 180* empty at highway speeds.

 

Why is that? Are they that anal about coolant mixture?

 

No but -40c is reality every once so often. You can't run that little coolant up here year round and I won't be swapping back and forth every season.

In any case I can tell that no one has an answer to my question. Yes, I know that higher temperatures in the coolant mean higher temperatures in the engine and possible additional wear. However I wanted to clarify what level correlates to what wear and the safety of each level. Even offroad people can't agree on where the red line starts for coolant temperature, let alone the yellow for caution.

As for transmission temperatures... those are totally unrelated since the systems are separate. Plus you can run a transmission at 250f for thousands of kms with no issues even though it's not good for it nor would I recommend it. All you would have to do is change the fluid more regularly, there is a chart floating around about it. I was hoping to find something similar for the 1 GR or maybe a pressure rating for the head.

Also, just to step back, I'm running around 190 f when I clean off my radiator and offroad I rarely see temperatures past 200 f. However on my last run there was more soupy mud then usual and my fan chucked it all over the radiator from the inside. My temperatures where anywhere from 200 to 230 f briefly. I did shut down once the temperatures spiked and I ran the heater which helped keep things cooler but, again, I was hoping for a better guide on when to bring cautious and when to freak out other the just opinion.

 

If I wanted opinions I would just turn to my local OR club... which is all over the map about this. Some guys don't even want to see 200f. Some say that Fords don't even open the thermostat all the way until 220f so it's no big deal. Others say that because the red on our dummy gauges is around 240 or 250 f that the engine can take those temps as long as it's only for a short time. If anyone has any fact based info I'd really appreciate it.

 

Ahh. I understand your concern for not being able to run a higher water to coolant mixture. Makes sense. Remember that coolant is just a lubricant/ anti boiling/ anti freezing additive so as long as you got enough in there to chemically change the properties o the water you should be good to go.

That being said, one thing that is definitely something for you to think about is the fact that the engine operates most efficiently at lower temperatures, around 170-180 is good. The reason they go higher than that from the factory is for emissions purposes. The hotter the engine is the more it is capable of burning off emissions better. Doesn't necessarily mean that it will allow the engine to run more efficiently.

Personally, I don't like seeing ANY engine go over 210. At that point I start to get nervous and get concerns over potential possibilities of overheating. I don't monitor my temps much if at all, which I should especially during sweltering summer, but I don't tow or do any taxing beatdowns on the engine either. As ling as my upper and lower hoses close to match in temp, and are in a less than 200* range, I am happy.

 

Yeah in Canada at -40 c you need to run at least 50/50 coolant with the Toyota stuff. Actually all trucks in Canada from Toyota come with 55/45 premix and that's what I'm still running. IIRC Ford and GM prefill with 60/40 of their stuff. Your basic premise is right, the coolant is the most needed in the mixture to extend the temperature range in which it's still a liquid, however the concentration at which it's present has a huge effect on how large that range is. To get down to -40 c and not have issues you need to run a much higher ratio of coolant than 20/80. From what I've seen that ratio is only good for warm weather climates where it doesn't go too far below freeze.

Coolant, when mixed with water, actually has a lower heat capacity but higher heat conductivity then water. So while it doesn't absorb as much heat it can absorb and dump it more readily. That's why most guys run 20/80 rather than distilled and a wetting/lubricating agent like was popular 20 years ago. More water coolant means more heat can be generated before the system is saturated but, a little coolant not only protects from corrosion and lubricates the pump, coolant also helps transfer the heat faster through the coolant (better efficiency warming and cooling as needed).

Alone coolant has a lower heat conductivity then water which is why pure coolant or too high of a mixture results in poor cooling performance.

Yeah I don't like seeing over 200 f either. I wasn't trying to say I did so my bad if I came off that way. I just want to know where is my shutdown temp and should I be looking into a better cooling system. I'm thinking about going to electric fans since that would put less draw on the engine and allow me to set the temperature where they come on full blast lower. I really don't think I'm beating on this engine when I ask it to work offroad. However it seems like this engine is very susceptible to heat buildup when there is mud on the rad and the supercharger on the engine.

 

With some answers already in, I thought I would still give my info. My Ultra Gauge stays at 185 most of the time and dips to 182 from time to time. On a hot day last week it went to 194 and freaked me out a little, but I put the UG in last October so I haven't verified summer temps yet. I mainly drive highway, 33 miles at a time. I use Mobil 1 synthetic oil if that matters at all.

 

You should clean between your radiator and ac condenser. I made a special spray wand that fit down between both and was able to remove a lot of mud from mine. Temp will be back to normal once you get it cleaned out. You really can't do that with just a hose or even at the car wash. I know others that have actually removed the radiator to get it clean.

 

I monitor my temp with a Bluedriver and 225 wouldn't sit well with me at all. Highest I've ever seen was 205. Probably OK for short time but something to be aware of most definitely. It's good that you are monitoring your temps. Most relay in idiot gauges and lights. Something to play around with is to be running your a/c wide open on a hot day. Check your temp. Then switch a/c off and blast your heat. Can drop a good 10 degrees rather quickly. Most on this forum are aware of this fact but it's cool see it digitally.

 

Pretty sure Coolant raises the boiling point of the water in the coolant system, which would make it cool more (near and over 200*).

Too answer the OP I normally see 185-190 on my Torque App.

 

Try a foaming coil cleaner like HVAC guys use on houses/buildings. I found some at Home Depot that specifically stated ok for plastics, rubber, automotive radiators.
Only use when engine cold. Rinse thoroughly.
Loosen fan shroud and remove grill so you can get better access to spray.

I've done it 3 times since last wheeling trip. The foam still brought out some mud and i bet it would still get more if I try again. Foam works best going into dry. Spraying on a wet surface doesn't do as much.

I run 185-190 steady now. Don't know what temp was before I cleaned but the OEM temp gage had been a couple lines hotter than it shows now.

 

Actually this is what I did. Running the heater with the windows down kept me at or around 200 f.

 

Yeah our temp gauge is definitely a dummy. At 225 f it had barely moved.