Does my radiator have an engine oil cooler?

j91z28d1 said:

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.

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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.

NELLY1947 said:

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.

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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

Doubeleive said:

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.

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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.

Timz71 said:

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.

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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.

Marky Dissod said:

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.

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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?

tahoecowboy said:

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

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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.

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.