Difference between a tranny cooler and engine oil cooler?

Oil coolers also help the oil warm up to the proper temp quicker when they are using the engine coolant to control the temp.

My Ford 6.2 has one and my Nissan Titan had one.

Good stuff, Ben.

Let me just add that the purpose of an engine cooler is to supply cooler oil to the bearing surfaces. Most people may be unaware of the fact that oil is very responsible for transferring heat out of the engine and is just as important as the coolant in the radiator.

In severe conditions an oil cooler can be essential. So if you operate in high temperature areas, high elevation areas, are carrying/towing a big load, an engine oil cooler can substantially increase the expected life span of your engine. Just remember when changing oil that the cooler takes a little bit more to be properly full.

sheripoms wrote:
I have a 2008 Tahoe and I am buying the B & M tranny cooler for it but do I also need a engine oil cooler? And what exactly is that?
Also If I do need one , which kind should I get?
Thanks so much in advance.

First some definitions and a bit of explanation of what/how/etc

Radiator...radiates heat. AKA heat rejection. AKA heat exchanger. Basicly
moves heat from one area/media to another. Your heater core underneath/in
the dash is a radiator

The principle is temperature differential between one side of the
cooler (inside liquid in this case) to the other side (outside surfaces
radiates to the cooler air). If there is no differential, there is
no transfer from one side to the other. The greater the differential
the more heat (energy) is rejected and the faster it is rejected. On
that, the types of material (brass, aluminum, etc) determine the rates
or throttles the rates of rejection. Best thermal conductor known
to mankind is diamond, but that is too expensive for this application

That was materials, now the types of architecture. Most common is tube
and fin. Tube can be round, or flattened into an oval. Fin stock is
punchered and slipped over the tubes. Some are done there, others or
better ones braze the fin & tubes together.

Another is plate type. No tubes, nor fins per say. But stamped sheetmetal
upset to form one half of a clam shell cavity. Mirror image and when
they are stacked every other one facing one or the other...they form
cavities for the internal fluid. Brazed together and they look like
stacked cavities (internal) and gaps between each sandwich that has
the outside air to flow.

Think of two pie pans, but with formed areas that when inverted to
mate with another, but turned/flipped/etc, will touch in those areas.
A paste like but is brazing material is screened onto those high spots
and when they touch, form a brazing junction. Then induction heated
to melt that paste (which also has flux) and brazes those high spots
together.


Stacked plate is NOT good for high pressure and why high pressure
liquid setups will always be tube/fin.

That is the basics for architecture and some of the details are stuff
like laminar/turbulent flow (laminar will have hot air and not mix
with the colder air next to it...turbulent is something that messes
up the flow to mix most to all the air. Meaning that you can have a
hurricane, but laminar and XYZ amount of rejection vs one with
turbulent, which might have 2 times the rejection rates

The reason for the need is that there are losses with any ICE (internal
combustion engine) and Automatic Transmission (Manual trannies do
to, but most do not need an external heat exchanger)

Towing is on the extreme end of needing heat rejection. The lube will
both break down if too hot and its lube properties reduce as the temp
goes up...till it oxidizes (burns). Some can be over cooled. Like ATF
needs to see or be above a certain temp, as the over night condensation
mixed with ATF can and does create acidic conditions that can and
will eat metal parts (sizing for your application and locality very
important)



So engine oil coolers are normally tube/fin and the smallest of the four
kinds (heater, main radiator, eng oil and ATF)

Ops forgot about another radiator (heat exchanger) and that is the AC
system. It really has two. One that produces cold gases that draws
heat from the interior. The other is a tube/fin radiator up front
that rejects heat to the outside air. Tube/fin because this system
has the highest pressure of them all.



Do you need an engine oil cooler? Depends...where you drive, how
you drive and what you haul/tow. Or any matrix of those conditions.

A lot of that depends on where you are in reference to the OEM's
specifications (Ratings). The OEM has installed both standard
equipment and optional equipment in reference to their
Specifications/Ratings for the worst condition they spec'd this
vehicle for (ratings)

Redsky wrote:
Synthetics can be worse for engines operating under high temperatures. almost all of them are 5W40 formulations and the engine manufacturers specify this weight for sub zero driving conditions and air temperatures under 90F degrees. In hotter weather they specify a 15W40 motor oil regardless of whether it is a mineral/dino or synthetic motor oil. You do not want to be starting the engine with a 5W oil on a 100 degree day and waiting for it reach 15W to be properly lubricating the engine bearings.

You do not have any understanding on how a multi grade oil works.

the bear II wrote:
Also consider putting some Royal Purple "Wetter Water" in the radiator. It's a product sold at most auto supply stores. You put it in the radiator and it helps to keep the temperature down when going up hill or towing.

I would be careful adding anything to any GM with Dex-Cool coolant in it!

Don

The coolant in the radiator flows through the engine block to keep the engine and the motor oil at the proper temperature. In some cases the manufactures have put a single thin radiator core in vehicles and there was space for adding a standard thickness core if the vehicle had the "tow package". The manufacturers charged extra for something they used to include in their trucks. This same tow package will include a transmission cooler.

Synthetics can be worse for engines operating under high temperatures. almost all of them are 5W40 formulations and the engine manufacturers specify this weight for sub zero driving conditions and air temperatures under 90F degrees. In hotter weather they specify a 15W40 motor oil regardless of whether it is a mineral/dino or synthetic motor oil. You do not want to be starting the engine with a 5W oil on a 100 degree day and waiting for it reach 15W to be properly lubricating the engine bearings.

I view towing as a severe duty use of the engine and transmission and adjust the oil and ATF service intervals accordingly. I change the oil every 7500 miles and at that interval there is absolutely nothing to gain with a synthetic even if it was the proper 15W40 oil.

25% of what goes into motor oil consists of additives and it is this mix that has the greatest impact on engine wear and longevity. The benefit of these additives decreases with engine use and so measuring only lubricity ignores this completely. Fresh oil means a fresh batch of additives as well. This is even more important with diesel engines as the changing of the motor oil takes out the soot and sludge that accumulate in the oil in the crankcase.

With transmission fluid there is a recommended replacement interval based on months as well as miles. Allison recommends replacing the ATF every 24 months or 50k miles whichever comes first if a TES 389 ATF is used, and every 48 months or 150k miles if TES 295 ATF is used. I use a ATF 295 to double the change interval for the transmission in my truck.

IMO engine oil coolers are not needed with todays new engines and oils especially in a Tahoe.
Save your money.

The tranny cooler cools the fluid that circulates in the transmission. It is a different type of fluid and is separate from the engine oil. A trans cooler is a must have for towing, but I don't think you need to bother with the engine oil cooler. The engine coolant would overheat before you'd ever have a failure due to overheated engine oil. Most of it has a flashpoint of over 400*F. Synthetic is better in this regard and might be cheap insurance for high temp situations.

Also consider putting some Royal Purple "Wetter Water" in the radiator. It's a product sold at most auto supply stores. You put it in the radiator and it helps to keep the temperature down when going up hill or towing.

An engine oil cooler is pretty much like a small radiator but cools the engine oil. Have someone take a look at it, you may already have one as standard equipment.