Chevy Colorado & GMC Canyon banner

1 - 20 of 28 Posts

·
Registered
Joined
·
4,032 Posts
Discussion Starter #1
Okay, the title is one possible answer to my issues, but here's what I've been thinking about.

When towing there seems to be a high correlation between coolant/oil/transmission fluid temperatures. That makes a bit of sense in that both the engine and transmission are working hard, and also at least the oil and coolant have a direct heat exchanger (I'm not certain if the transmission cooler is cooled by coolant or air, but I think it's coolant).

So looking at coolant temps rising, is that driven by the oil temperatures driving up the coolant temperatures? Or stated differently, are the temperatures of the radiator coolant not rising significantly, it's just the oil heat flowing into the engine coolant? (Basically the sensor is sensing at a point after the oil heat exchanger.)

Similar issues with the transmission temps, but there I would assume that IF the trans cooler works off of not only coolant, but coolant at the bottom of the radiator, that the coolant would be cooler there and should cool the transmission better. But transmission temperatures do rise and seem to take a long time to cool down even once coolant temperatures fall. So maybe that transmission cooler is simply undersized.

Thoughts?
 

·
Registered
Joined
·
90 Posts
By default, the lower part of the radiator is blocked off. Remove those panels and you'll notice better temps immediately.
 

·
Registered
Joined
·
4,032 Posts
Discussion Starter #3
By default, the lower part of the radiator is blocked off. Remove those panels and you'll notice better temps immediately.
I'm aware of that. I suppose that is in effect a larger radiator though, so I appreciate the answer.
 

·
Registered
Joined
·
1,254 Posts
Towing 6k travel trailer in the mountains during hot summer temps, I have never overheated ,coolant,oil or trans. Not with my 2016 or my 2020. This tells me that no added cooling will ever be needed for this setup. I have not removed the panels, nor will I need to.
 

·
Registered
Joined
·
4,032 Posts
Discussion Starter #5
Towing 6k travel trailer in the mountains during hot summer temps, I have never overheated ,coolant,oil or trans. Not with my 2016 or my 2020. This tells me that no added cooling will ever be needed for this setup.
I didn't use the word overheated, but all the numbers can easily go up 40 degrees. Still within safe range, but significantly higher.

But again the issue isn't just bigger radiator, but also what is driving what? Why are they going up in tandem (besides the extra work the engine and transmission are doing). Is the oil getting up to 210 because the coolant is getting up to 210, or visa versa?
 

·
Registered
Joined
·
1,778 Posts
I do not tow anything too heavy, but do drive up mountain grades that can go over 11K in elevation, and have gone over the "Ike Gauntlet" many times. Truth be told, Vail Pass is way tougher than the Ike Gauntlet, but I digress...

From what I have seen, engine coolant temps, even going up those grades and in thin mountain air, which reduces cooling efficiency, does not cause any coolant temp concerns. It takes a lot to get the water temp over 200F from what I have observed via using OBD Fusion on my phone. This is running a GDE tune, which may influence that vs. stock too though. Oil temps are always a bit higher than water temps - the oil is sprayed under the pistons by jets to carry away heat. If the engine is working hard, oil temp will go up, but 210F is typical for many engines, and nothing alarming at all when it comes to oil temp, especially with a good synthetic oil.

The trans does run warmer than I would prefer. Removing the panels and adding a PML pan seems to have blunted the trans temp nicely. Also running a trans tune which is much "tighter" than stock, that probably helps keep temps down some too. Modern trans fluid, especially good synthetic stuff, does not mind the temps we are talking about at all. I still prefer temps below 200F though, as sustained higher temps than that shorten solenoid life. Even with my mods, temps can go over 200F, but not typically. Have considered a cooler but believe for my use it is good enough at this point.
 

·
Registered
2018 GMC Canyon Diesel
Joined
·
73 Posts
Unlike the V6 with the towing package, the Diesel doesn't have a separate oil cooler for the transmission. Our transmission cooler is built into the radiator. Several people on the forum have had good results adding aftermarket transmission cooling radiators, which I intend to do next year (considering I woke up to 2+ inches of snow this morning, crawling around under the Canyon isn't something I want to do).
 

·
Registered
Joined
·
34 Posts
No, the coolant is not overheating the oil. Nor is the opposite happening. The oil/coolant heat exchanger will assist with reducing the time required to get up to operating temperature and reduce oil temperatures when oil is hotter than coolant. The greater the difference between the two the higher the rate of transfer of energy from one to the other. Larger cooling capacity will reduce the magnitude of temperature spikes decrease the rate of change.
The coolant, oil and transmission temps climb and drop in unison because of changes in load and RPM. That will happen no matter the size of the radiator.
The main source of heat in coolant is from the combustion chamber. Temps in oil, engine and transmission, are driven almost entirely by friction and are virtually independent of load. Friction of course is rpm based. More revs=more heat.
Hopefully this makes some sense. I can post relevant graphs and research papers if you want to travel further down this rabbit hole!
But to answer your question(s) in the original post, no the truck doesn't need a larger radiator as it is well matched to the capability of the truck and it's intended uses. Over cooling can cause issues as well. It's a false assumption that cooler=better. Transmission temps take a while to drop after coolant temperatures drop due to the mass of the transmission. That includes all the oil and metal; and there's lots of each.
 

·
Registered
Joined
·
46 Posts
No, the coolant is not overheating the oil. Nor is the opposite happening. The oil/coolant heat exchanger will assist with reducing the time required to get up to operating temperature and reduce oil temperatures when oil is hotter than coolant. The greater the difference between the two the higher the rate of transfer of energy from one to the other. Larger cooling capacity will reduce the magnitude of temperature spikes decrease the rate of change.
The coolant, oil and transmission temps climb and drop in unison because of changes in load and RPM. That will happen no matter the size of the radiator.
The main source of heat in coolant is from the combustion chamber. Temps in oil, engine and transmission, are driven almost entirely by friction and are virtually independent of load. Friction of course is rpm based. More revs=more heat.
Hopefully this makes some sense. I can post relevant graphs and research papers if you want to travel further down this rabbit hole!
But to answer your question(s) in the original post, no the truck doesn't need a larger radiator as it is well matched to the capability of the truck and it's intended uses. Over cooling can cause issues as well. It's a false assumption that cooler=better. Transmission temps take a while to drop after coolant temperatures drop due to the mass of the transmission. That includes all the oil and metal; and there's lots of each.
Good post, but there is some clarification needed for the highlighted part.

Load and therefore an increase in produced power and the associated waste heat can increase independently of RPM, e.g. adding payload to the vehicle and/or climbing a grade, but maintaining the same speed in the same gear. You can see this more easily if you have an exhaust pyrometer as it will act much more rapidly than the engine oil or coolant temperature gauges (as is the case with many semi trucks).

When pulling a heavy load and/or climbing a steep grade there is a happy medium where the vehicle is in the right gear, maintaining an acceptable speed (for the given operating parameters), is shedding heat appropriately and; if it is a long, steep grade and/or maximum payload/towing, is being operated at part throttle (you can tell the guys that only know "pedal-to-the-metal" because they're parked on the side of the road with the hood open and steam rolling out. Also really dumb; don't park on the side of the road with a roasting engine unless it's already a terminal situation... because it's about to become one). At some point in the throttle position/load/speed equation you go past the point of balance and adding more fuel no longer increases the speed, but adds significantly to the waste heat.
 

·
Registered
Joined
·
4,032 Posts
Discussion Starter #11
Load and therefore an increase in produced power and the associated waste heat can increase independently of RPM, e.g. adding payload to the vehicle and/or climbing a grade, but maintaining the same speed in the same gear. You can see this more easily if you have an exhaust pyrometer as it will act much more rapidly than the engine oil or coolant temperature gauges (as is the case with many semi trucks).
I was going to respond to that post that it's more about fuel consumed over time than rpm/friction.
 

·
Registered
Joined
·
127 Posts
What people forget is the oil temp of these motor does get very hot. And it might not over heat but the ecu does Derate the power as temp rises
All anyone has to do is watch tranny temps oil temps and water temps on scan tool and can see the rise of temps in towing and hot days
 

·
Registered
Joined
·
127 Posts
My set up is different than most. I ditched the clutch fan set up. And modified a Ford system flexa lite aftermarket electric fan set up. But I also have a tranny cooler with a fan I do tow everyday and I tow in the desert of AZ in heats of 110-121. With my set up I can control the heat but I still monitor the oil temp and would like to control it better. And plan on removing the oil cooler and building a plate to go on it so I can add a larger oil cooler
 

·
Registered
Joined
·
781 Posts
What is the issue? ATF temp? Oil temp? What numbers give you concern? Just boosting post count?

Engine losses drive radiator
 

·
Registered
Joined
·
4,032 Posts
Discussion Starter #16
What is the issue? ATF temp? Oil temp? What numbers give you concern? Just boosting post count?
Probably transmission temp is the biggest concern and oil temp the least.

I think maybe the panel removal suggested first might be the best solution, but that's something I've avoided because seemingly GM has put them there for a reason (that they don't seem to want to disclose). But effectively that does make a bigger radiator, or at least one with more air flow. At this point of the year I suppose it doesn't really matter much and a decision can wait for Spring.
 

·
Registered
Joined
·
127 Posts
Radiator seems to be large enough. Just add a tranny cooler if that the area your worried about and you can keep towing temps under 200-205 during any tow situation
 

·
Registered
2017 All Terrain 2.8L CCLB Dark Slate Metallic
Joined
·
970 Posts
Probably transmission temp is the biggest concern and oil temp the least.

I think maybe the panel removal suggested first might be the best solution, but that's something I've avoided because seemingly GM has put them there for a reason (that they don't seem to want to disclose). But effectively that does make a bigger radiator, or at least one with more air flow. At this point of the year I suppose it doesn't really matter much and a decision can wait for Spring.
Think about it, what is in those slots on a gas truck? There are normally active shutters there, so one reason would be the block out panels are for aerodynamic benefits. This could include MPG savings, or possibly even to help the engine reach the intended running temperature quicker (such as a radiator blanket for cold weather). The cold air intake is also right there next to the panels (two square holes) so they would also serve the added benefit of ramming more air into the fender well, and in turn feeding the airbox.
 

·
Registered
Joined
·
4,032 Posts
Discussion Starter #19
Radiator seems to be large enough. Just add a tranny cooler if that the area your worried about and you can keep towing temps under 200-205 during any tow situation
If I put that cooler before the existing one that might answer my question of which device is driving the similar temperature increases. Put before the existing cooler system would likely be raising the temps if the new was was large enough.

I think the less extreme solution of panel removal and replacement is probably a better place to start, removing them only when towing either in extremely hot weather and/or over a decent pass (e.g. not Snoqualmie or Tiger passes).
 

·
Registered
Joined
·
615 Posts
I regularly see temps of 199* empty and 220-237* F when towing our 4000 lb camper, on days of 70*F. I also think (as I have said before) a trans cooler is in our trucks future as well.

I can't imagine what the temps would be if towing our camper in Joshua Tree area when it is 114*F, which is what it was when we were there with our truck, not towing.
 
1 - 20 of 28 Posts
Top