Oil cooler - anyone done it?

So for various reasons (boredom, mainly, + 12 lbs oil pressure when the engine gets to a *hot* idle) I'm thinking about adapting one of the spare oil coolers or heater cores kicking around the shop to be an oil cooler in the Jeep.
I think I'd mount it behind the front cross member. Limited airflow with the stock bumper, I know, but should help. Could also drill speed holes in the front bumper skin, I suppose.
My idea for plumbing, so far, is a remote mount oil filter kit from (somewhere) & splice lines to / from the oil cooler into the return line. It would run engine -> filter -> cooler -> engine. I imagine the filter would be less impedance and more effective when the oil is hot.
Does this make sense? Anyone done this before?

Sounds like it should work as long as the cooler can handle up to about 60PSI.

I will be adding one this coming summer. There are two things you really need to factor in.

First and foremost is that a transmission cooler will not work as an engine oil cooler. Too restrictive. Engine oil coolers use a 0.500" minimum hose line.
Second is that you must have a thermostat for the cooler so that you do not over cool the oil.

Best bet is to buy a kit that has a thermostat equipped sandwich adapter if you have never done it before. Otherwise, you can pice a system together which is what I will be doing.

I will be mounting mine on the inside of the front skid with a fan on it next to my transmission cooler that is rigged in a similar fashion. Only diffference is that I have the fan on a thermoswitch so as to not over cool the transmission in the Winter. I will be putting a thermoswitch on the oil cooler fan as well as well as a mechanical thermostat on the feed line. Done properly, you can expect up to 10 pounds better idle oil pressure.

I have put engine oil coolers on everything I have ever owned with the exception of my Mercedes which came with one from the factory. Then again, I put a cooler on the return side of the power steering line also...

So, why all this stuff about thermostats? The oil must reach a minimum operating temperature to drive out moisture. Most recommend 180 degrees, other 200 degrees. I prefer the 180 degree solution.

Kits generally come with a 180 thermostat.

yossarian19 said:

I think I'd mount it behind the front cross member. Limited airflow with the stock bumper, I know, but should help. Could also drill speed holes in the front bumper skin, I suppose.

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I was actually thinking about that setup for a transmission cooler, I thought cutting slots into the bumper would be good to get airflow and not look horrible. Could have a transmission cooler on one side and an oil cooler on the other.

o-gauge-steamer said:

I will be mounting mine on the inside of the front skid with a fan on it next to my transmission cooler that is rigged in a similar fashion.

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I'd like to see pics of the cooler mounted to the front skid, I also thought about that. I started to get worried that if I actually hit something with the skid then I would be in big trouble dumping fluid. Being at +2" my skid would not be up and out of the way really so I don't think I would go that route but still curious to see that setup.

I'll post up some pics. Keep in mind that right now I have dropped the skid 3" to clear the sway bar. Once the sway bay is replaced with an Currie Antirock, I will be moving the skid back up to it's normal mounting location.

I mounted it there as I was chasing an "overtemp" issue. Not a big one, it just was not where I wanted the thing to run. What I got for moving the cooler out of infron of the radiator was 5 degrees C less operating temperature. The Heep runs between 195F and 201F all day, every day. But then, I have replaced all of the mechanical cooling with electric...

What prompted me to move it was the conversation I had with the good folks at Davies-Craig. They are a well known (in Austrailia) company that has a very little presents here. They said that I neded to get a bit more air across the radiator so I moved the cooler out of the way. Made sense that it was not only blocking the air flow but it was warming the air as well. We all know just how fragile our cooling systems are...

I never liked the idea of an auxiliary cooler in front of the radiator it just never made any sense to me.

A ZJ trans cooler fits well behing the front cross member, and works quite well as a PS cooler, or trans cooler

I used this http://www.jegs.com/i/JEGS-Performance-Products/555/51710/10002/-1?parentProductId=1032937

And a plate/fin cooler under the jeep (street jeep)
I sit in traffic, stroker, ac on full blast.

I like the extra cooling capacity, keeps the oil from breaking down, and i didn't block the ac condenser/radiator.

That said, I wouldn't mount the cooler there on my woods toy.

I use a PS cooler from a Ford F250 on my Heep, Put it in front of the cool side of the radiator as the maximum heat transfer is, obviously, right in front of the mechanical fan. In my case, I have the electric fan running on low to reproduce the effect of the mechanical. Alternator cooling...

The sandwich adaptor looks pretty good. Keep in mind that a proper thermostat will bypass approximately 10% of the oil to the cooler at all times. This is done to prevent thermoshock when the t-stat opens.

I will be relocating my filter when I do mine so will be using a t-stat similar to http://www.jegs.com/i/Derale/259/25719/10002/-1 to control the temps. Just need to find a better place for the filter. If only there was room...

Hesco sells an oil cooler/warmer. However, you can't run a longer oil filter with it. I'd be more interested in the warmer part. It takes a while for the oil to get hot.

can I ask why? Once oil reaches about 210 degrees, it's at optimal viscosity for operation. Cooling it down from there will only make the engine work harder to pump it and result in higher viscosity and less lubrication. If your cooling system is working properly, the oil shouldn't get too hot - it changes temperature MUCH slower than coolant does (which is why it's efficient at cooling).


If you're worried about it breaking down, switch to synthetic oil - it doesn't have that problem

Why not a remote filter if you're running a sandwich plate anyway?

dukie564 said:

it changes temperature MUCH slower than coolant does

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That is why I would want a warmer. To bring it up to operating temp faster and start burning off water faster

dukie564 said:

can I ask why? Once oil reaches about 210 degrees, it's at optimal viscosity for operation. Cooling it down from there will only make the engine work harder to pump it and result in higher viscosity and less lubrication. If your cooling system is working properly, the oil shouldn't get too hot - it changes temperature MUCH slower than coolant does (which is why it's efficient at cooling).


If you're worried about it breaking down, switch to synthetic oil - it doesn't have that problem

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I live in Georgia. I commute in Atlanta traffic. The jeep has a 4.6 high compression stroker. The AC never goes off. I drive the piss out of it (why else put in a stroker?)

Getting the oil up to temp is never an issue for me. More cooling capacity is always welcome in my case.

Cooling an engine is about surface area. The radiator exposes engine heat from deep in the engine to a giant heat sink ( the atmosphere). The oil cooler does the same, if less efficiently.

If over cooling the engine oil is a concern for you, there are thermostatic valves http://www.batinc.net/thermos.htm available.

Also, I run synthetic oil + zinc additive, a separate trans cooler, do regular coolant changes ect....
An oil cooler is just one more durability enhancement in my eyes

bigdaddyjlove said:

I live in Georgia. I commute in Atlanta traffic. The jeep has a 4.6 high compression stroker. The AC never goes off. I drive the piss out of it (why else put in a stroker?)

Getting the oil up to temp is never an issue for me. More cooling capacity is always welcome in my case.

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Do you have an oil temp gauge?

On A previous, similar build, that my daughter drives (wrangler). I haven't installed one on this jeep yet.

I have used an infered thermometer to check oil pan temp at the end of my commute, and other driving. Even this time of year with a.m. Temps in the 30s, the oil pan is at 200 - 215. Not perfectly accurate, but I'm satisfied.