Does my radiator have an engine oil cooler?

[NELLY1947]

I can tell you from personal experience with oil cooling, the end tank oil coolers work very well. you'd need a huge front mount to match the cooling. enough that you'll end up blocking air to the radiator anyways.


nice neat package. in a high end race application the stock lines are a bit flow restricted thou. but usually there's a high pressure bypass in the block above the filter.

What year/model is you unit. Also i might not be correct but is the oil engine or transmission (red or black).
Sorry but I'm old school and it is transmission in the rad. reason engine you want to keep as cold as possible. So separate cooler if you have one. Transmission you want hot (to a point) so with the rad/Waterloo to heat it up before moving.

 

[j91z28d1]

What year/model is you unit. Also i might not be correct but is the oil engine or transmission (red or black).
Sorry but I'm old school and it is transmission in the rad. reason engine you want to keep as cold as possible. So separate cooler if you have one. Transmission you want hot (to a point) so with the rad/Waterloo to heat it up before moving.

tranny fluid (red) runs thru the passenger side radiator end tank. the radiator has tons more cooling capacity under all but the most extreme conditions and water to fluid heat transfer is very effective. a small core inside can knock down Temps much better than air in front of the radiator. I personally don't agree you need to warm tranny fluid, it's as thin as water at room temp and compressed to very high pressures, which adds heat. but I base that off nothing besides my experience and I don't live in Alaska or something. running it thru the end tank is for cooling more than warming, I have a feeling tranny temp without a cooler would get hot before the engine on a cold morning at idle anyways. compressing a fluid to high pressure adds tons of heat.


there's a great towing add on cooler thread around here somewhere. guys tested all kinds of configurations. a large front mount alone didn't cool as well and raised coolent Temps by blocking air flow. the best they found was a large add on cooler in the front mounted down low and opening up the fake lower grill, running fluid thru the radiator first and then down to the large add on and then to the tranny.


today's good oil can handle higher temperature for short amount of time without engine damage. I've send well over 300deg oil Temps in track cars without any engine damage, just needs to be changed often. shouldn't be doing 10k mile oil changes with abuse like that. so being that your also can't have two coolers in the same end tank, that leaves the drivers side the only place for the oil cooler from the factory. it is a bit hotter over there, the coolent gauge is located in the cylinder head near the exit. so that should show the max water temp your oil cooler gets run by it, oil sees that or less, which is fine. honestly, these trucks don't have physical oil temp sensors, what's reported to the scanner is just some math the ecm does. if you used this as a tow vehicle (or added boost) and wanted to know actual temp, you'd have to add on a external sensor. I wouldn't worry about it for the average driver. only the guys towing huge rv's in the mountains would I be worry about the oil Temps, especially if you have the factory option that routes it thru the radiator to keep it in check. that and these afm trucks need frequent oil changes anyways.

so yeah red passenger side, black drivers side

 

[Timz71]

those lines are for the power steering cooler which is a separate piece, not part of the radiator, it does look like it might have the option for it on the radiator end cap but the fittings are not there and if there is no plug in it then it's likely contaminated anyway. you can add a oil cooler if so desired with a adapter plate, 2 lines and a radiator

*also if the radiator does have a oil cooler it doesn't matter, that part just isn't used if you do not have the lines for it.

I have a 2002 Z 71 all factory, it does in fact, have an oil cooler, a separate power, steering cooler, and a large transmission cooler, I was under the impression that all Z 71 off-road have the factory oil cooler, check the list on the inside of the glove box door, it shows all the codes that correspond to your truck by serial number. However, you can verify by looking to see if there is, a aluminum adapter With two hoses connected to it Between the engine block and the oil filter.

 

[Doubeleive]

I have a 2002 Z 71 all factory, it does in fact, have an oil cooler, a separate power, steering cooler, and a large transmission cooler, I was under the impression that all Z 71 off-road have the factory oil cooler, check the list on the inside of the glove box door, it shows all the codes that correspond to your truck by serial number. However, you can verify by looking to see if there is, a aluminum adapter With two hoses connected to it Between the engine block and the oil filter.

the pictured vehicle by the OP DOES NOT HAVE A OEM OIL COOLER
it's real easy to see that. now if someone altered it from stock, that is unknown, sometimes people delete the oil cooler and use a block off plate because the lines are prone to leaking and it's a lot cheaper to delete than replace.

 

[tahoecowboy]

Y'all keep calling the radiator's motor oil tank an oil 'cooler' - it's a heat exchanger.
It's actually meant to help motor oil reach minimum operating temp sooner.

However, once the motor oil reaches or exceeds minimum operating temp,
the coolant is actually warmed by the motor oil -
motor oil would be even hotter and coolant cooler if kept separate,
which can also increase oil consumption.

This is interesting, I thought that most engines have a thermostat that prevented the coolant from leaving the engine until it was at "minimal" operating temperature. Man, you got me thinking, why do they call it coolant if it is ran through a heat exchange, and used to heat the oil, isn't it a heatant at that point?

 

[Marky Dissod]

... thought that most engines have a thermostat that prevented the coolant from leaving the engine until it was at "minimal" operating temperature.

This is true. It's engine coolant, because it keeps the engine from overheating.
However, vis a vis the ATF heat exchanger, engine coolant also serves as an ATF heatant,
because ATF would always run cooler without the radiator's ATF heat exchanger.
(UNDER normally intended operating temp, it's good to warm up the ATF quickly,
but once the ATF reaches minimum normal operating temp, it doesn't need to get any hotter.)

The radiator's motor oil heat exchanger sheds heat from the motor oil to the coolant.
So, relative to the coolant, motor oil is the coolant's heatant ...
... and the coolant is the ATF's heatant.

 

[DaveO9]

I recently added the OEM oil cooler to my 2013 LT without the towing package. I replaced the rad with the Denso with integral oil cooler, and purchased the line set that includes the adapter plate. Pretty easy mod, HOWEVER, I was replacing the DS motor mount at the same time. Routing the new cooler lines would definitely have been more challenging with motor mount in place. Other than that, not too bad.

My oil pressure did drop up to about 5 psi with the addition of the cooler, just something to be aware of.

 

[jared999]

I recently added the OEM oil cooler to my 2013 LT without the towing package. I replaced the rad with the Denso with integral oil cooler, and purchased the line set that includes the adapter plate. Pretty easy mod, HOWEVER, I was replacing the DS motor mount at the same time. Routing the new cooler lines would definitely have been more challenging with motor mount in place. Other than that, not too bad.

I picked up the radiator with the transmission cooler option and some new lines, including the one with the baffle plate that attaches above the oil filter.

I see almost no room to run the lines on the driver side with the transfer case in the way. I found a YT video that suggests using a large wood block to spread out pressure and then jack up the engine carefully to give enough room, but I think this may damage the oil pan. I'm also wondering if the lines look the way my photo does, installed. I did a test fit (without the brass fittings which are not screwed into the radiator)

Can you or anyone share some photos of how the lines route towards the transmission? i.e. so that I can see what they go under / over. I've found a few YT videos but they are silverados and suburbans and none of them have 4WD, so they all have a lot of room to work with.

 

[Geotrash]

I picked up the radiator with the transmission cooler option and some new lines, including the one with the baffle plate that attaches above the oil filter.

I see almost no room to run the lines on the driver side with the transfer case in the way. I found a YT video that suggests using a large wood block to spread out pressure and then jack up the engine carefully to give enough room, but I think this may damage the oil pan. I'm also wondering if the lines look the way my photo does, installed. I did a test fit (without the brass fittings which are not screwed into the radiator)

Can you or anyone share some photos of how the lines route towards the transmission? i.e. so that I can see what they go under / over. I've found a few YT videos but they are silverados and suburbans and none of them have 4WD, so they all have a lot of room to work with.


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The driver's side of the radiator is for the engine oil cooler. The pax side end tank is the transmission cooler. The block-off plate above the oil cooler is for engine oil, which is what those lines are designed to mount on. Yes, I'm sure.

To get them in there, you'll likely need to remove the driver's side engine mount, the steering shaft, and the heat shield on the exhaust manifold. At least that's what I had to do on my 2012 XL Denali and it made the job a lot easier. I used a block of wood on the oil pan with a jack underneath, working gently to raise the engine just enough to get the motor mount out of the way. The oil pan can handle the weight - it's structural.

 

[Jdsfx1]

Hmm……my 08 Yukon looks to have an external oil cooler and external power steering cooler from the factory. Nothing is incorporated into the radiator, is this the tow package?

 

[donjetman]

Hmm……my 08 Yukon looks to have an external oil cooler and external power steering cooler from the factory. Nothing is incorporated into the radiator, is this the tow package?

All factory installed engine oil & tranny atf coolers come and go from the radiator.

like @Geotrash said, if there are lines in/out of the passenger side of the radiator? those are for the ATF/tranny, and lines in/out of the driver side of the radiator? those are for engine oil.
What is the rpo code (glove box)?
My 07 Yukon has a ps cooler and a atf cooler in front of the rad and the rpo code is KNP and is okay for light duty towing. No engine oil cooler or lines connecting above the oil filter and to the driver side of the rad.

 

[Geotrash]

All factory installed engine oil & tranny atf coolers come and go from the radiator.

like @Geotrash said, if there are lines in/out of the passenger side of the radiator? those are for the ATF/tranny, and lines in/out of the driver side of the radiator? those are for engine oil.
What is the rpo code (glove box)?
My 07 Yukon has a ps cooler and a atf cooler in front of the rad and the rpo code is KNP and is okay for light duty towing. No engine oil cooler or lines connecting above the oil filter and to the driver side of the rad.

My '07 XL Denali is the same - no engine oil cooler from the factory. However, when I installed a new radiator in 2023, I bought a Denso that has the engine oil cooler in it, along with a set of cooler lines. When it's time to replace the driver side motor mount again, I will install the cooler lines because we still tow heavy with it sometimes.

 

[jared999]

To get them in there, you'll likely need to remove the driver's side engine mount, the steering shaft, and the heat shield on the exhaust manifold. At least that's what I had to do on my 2012 XL Denali and it made the job a lot easier. I used a block of wood on the oil pan with a jack underneath, working gently to raise the engine just enough to get the motor mount out of the way. The oil pan can handle the weight - it's structural.

Got it, so that appears to be the way. Motor mount and jack it up a bit with a wood block. Thanks!

Right now I've got the new radiator in and have the motor mount basically out, so I'll fiddle around some more this weekend and finish it up.

 

[jared999]

Had to jack the engine up, move the motor mount out of the way (didn't actually remove it though). Move the heat shield and remove some crap near the oil filter so that I could get the lines through.
Having done it once now, I could do it much faster. I suppose that's how it goes for just about everything.