oil cooler to lower engine temp?

quick question:Will an oil cooler lower overall engine temp much?

my geuss is yes it will be able to run cooler and much better. i think it would have a good effect.

we used to run oil coolers on our turbocharged cars that have oil lines running to the turbo. the oil cooler kept the oil.. well cooler... specifically it made the oil last longer (too much heat breaks it down) since turbo cars can kill oil pretty quick with a hot turbo. I think some of the older porsches that where predominantly "aircooled" had oil coolers to help cool the motor too ( i'm running on hear-say from stuff i heard years ago on that). i could not imagine it hurting you in anyway, but it may be overkill for a daily driver in a cool to temperate climate.

i was thinking of doing the same thing and after i acquired a new flexalite setup i learned that oil needs to be hot to burn off moisture. an oil cooler added can actually harm your engine by not allowing this moisture to burn off at the higher temps. i dont have specificas but it was overkill for what i needed. i now have a flexalite oil cooler kit brand new sittin doing nothing. i lowered temps by going through my cooling system and making sure it was all in tune. im kicking myself for even buying the oil cooler. totally not needed.

jeepdeepfreak said:

quick question:Will an oil cooler lower overall engine temp much?

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No. Oil does not play a significant role in engine temperature control.
The engine runs best, with greatest power and efficiency, when the operating temperature is high.

Jim Mesthene said:

The engine runs best, with greatest power and efficiency, when the operating temperature is high.

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HUH?
If the posters' jeep is running at 210 and he is trying to lower the operating temp then I would agree, don't do it, the engine was designed to run at 210*. To say that an engine runs best when the temp is high could be mis leading.

Jim Mesthene said:

No. Oil does not play a significant role in engine temperature control.

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Uh, not true. So if you had a jeep running at 240* and you added an oil cooler you don't think that the operating temp would decrease? I would agree that the actual temperature reading on your gauge is the coolant reading but cooler oil = cooler running temp.

Hey all, just wanted to share some more thoughts.
the oil only has to be at or above the boiling point of water to get rid of the moisture in it....it definatly has this temp and i could not imagine a oil cooler chilling the oil lower than that. Think about a good tranny cooler getting temps to 180 degrees, and it doesn' have a combustion system inside it.
the Jeep 4.0's have cooling systems that should be able to adequatly keep the engine cool. If your car is running hot, work on the cooling system... not cooling the oil. If you are cooling the oil, it may help cool the motor ( but i don't forsee a big difference) but more importantly it will help maintain the longevity of the oil ( assuming we are talking about a small size oil cooler... no bigger than what most would run on there tranny's).
? to the poster... where you thinking about getting a unit that piggybacks onto the oilfilter housing or did you have something else in mind.

My two cents is that, though I've never seen an oil cooler on an otherwise stock XJ, I can't think of a reason to put one in, but can think of more than a few to not put one in. First, if you are having overheating issues, fix the problem with the cooling system. Second, and most important I think, is that most XJ I6's have enough problems holding the oil pressure at low rpm's, adding an air cooler and expecting the engine to push the oil through it seems like a bad idea.

heights houston made an EXCELLENT point on the XJ's low oil pressure...

it will help drop temperatures, but with a properly working cooling system you should only need additional cooling if you're doing something like desert racing or towing in a hot climate.

I've thought of putting an oil cooler in my XJ. Back from my racing days, it was kind of accepted knowledge that 180 degress was the ideal oil temp.
I always install a pan temp. sensor in the motor and tranny pan. If either gets too hot, I just shut it down for awhile, a lot easier and cheaper in the long run.
Bathing the motor in 180 degree oil has almost got to be a good thing, for longevity. And still warm enough for water evaporation.
A good one with a 160-180 degree thermo bypass, so the oil doesn't over cool is probably the best choice. And likely installing a high volumn pump, just in case, may also be a good idea. Synthetic oil with an oil cooler would also probably be a plus, synthetic typically has a more constant viscosity in variable temperature ranges.

My 3/4 ton Chev. with the heavy duty trailer package, has an engine oil cooler setup, that runs through the radiator just like a tranny cooler.

I have a fin and tube cooler that is stacked, two seperate tube systems in a common fin package, I may plumb it in and run the surge tank return through one set of tubes and the engine oil through another. The size is right to install it under the radiator, behind the bumper. It will likely work OK year round. I think I'll install a high volumn pump the next time I have the pan off and give it a try. Install a remote filter adaptor to tap the oil system. Just a thought, that may or may not work out, but sounds interesting enough to try.
I have most of the pieces on the shelf in my shop, it won't cost me much to experiment a little.
I'd still feel better about the whole thing if I could find a below 180 degree bypass. Summit used to sell them, though I haven't seen any recently.

To answer the freaks question, I'd say Yes, it will lower the engine temp. By how much depends on a number of things (such as the size and placement of the cooler).

As others have said, if you're trying to address an overheating problem, fix your cooling system first.

So let me make sure I have everything straight-

One person heard that the oil has to get hot to remove water, so the cooler is a bad idea.

Another person claims oil temp will have no effect on operating temps, but in fact oil is the only way to cool the bottom end of the engine (the bottome doesn't get as hot as the head, but there are still no coolant passages there).

Another has never seen it on an XJ, therefore is can't/shouldn't be done/work.


Hmmm. Anyone actually TRY an oil cooler?

Here is my experience- I had an oil cooler in my '95 F250 with the 5.8 motor. In the 8 years I owned the truck it spent about 40% of the time pulling a trailer, that's a LOT by comparison. With the oil cooler I never had temperature issues even pulling the larges loads on the hottest days (110+F). the Ford I had before that would get warm, but not overhead with less loads. My VW bug had a tendancy to run hot, as all air-cooled engines can, add an oil cooler and don't look back, never had engine heat trouble again. Water? Good hell, how hot do you think it has to be for water to evaporate? It boils at 212F at sea level, lower temps at elevation. If you use a thermostat controlled oil cooler that only allows oil into the cooler at 185F, your oil is plenty hot enough to drive water into the atmosphere, providing your CCV system is not plugged. There is a lot of splashing, turbulence and aeration going on in the oil pan as soon as the engine start, all of this helps the entrained water to dissapate. We aren't talking about 50F oil here that will stay as thick as 90W the whole time.
The problems I see with oil coolers stem from the pressure, I wouldn't be content to run some rubber hose with hose clamps from the filter to the grill and back. At 20-50psi the hose will expand and contract wuite a pit, and with the temp canges contribute to the accelerated deterioration of the hose. Steel lines or braided lines are bood, imo, but not rubber hose.

Summit sells a thermostatic bypass that sandwiches between the block and oil filter. At start up (cold oil) only 10% of the oil passes through the cooler, just to keep it flowing and warm all the oil. At 185F it opens fully and allow 90% of the oil to pass through the cooler. This keeps your oil at about 185F as long as you have a large enough cooler in front.

Is it worth it on the XJ? Sure, if you want to do it. Just like the electric fan mod, there are pros and cons that you have to be prepared for but wither way won't cause any earth-shattering changes.

When I build my front bumper it will have an oil cooler mounted in it, and plumbed with steel and/or braided lines, nothing rubber. I pulled the oil cooler off of an old F250 at the junk yard and if it only gives me a few (10-20) degrees of cooling, it will at least make the overall cooling system that much more resilient. But then I tow my trailer for camping, etc and find that I

SCW, I don't need experience with an oil cooler on an XJ to have an informed opinion about them, however, you do ask an insightful question. "Anyone actually TRY an oil cooler?"

OK, everyone with an oil cooler on their XJ raise their hand. I think the show of hands speaks volumes.

Not discounting the usefulness on a truck that tows 40% of the time, or an XJ built for racing or extreme engine stress, just discounting the usefulness on OEM XJ's.

Just another place to leak oil and loose pressure on a 4.0. I had a engine oil cooler and a dual filter kit on my 96' Bronco and when one of the lines decided to let go....well what a mess, oil everywhere!

cklaus said:

I think some of the older porsches that where predominantly "aircooled" had oil coolers to help cool the motor too ( i'm running on hear-say from stuff i heard years ago on that). i could not imagine it hurting you in anyway, but it may be overkill for a daily driver in a cool to temperate climate.

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All porsches were air cooled up through 96 until the boxter came out in what i beleive was 97 from that point on all of the porsches since then have been liquid cooled.

just a bit o knowledge cause knowledge is power.

oh i used to work for porsche. Cause i dint honestly knwo that until i worked with them every day.

19CHEROKEE89 said:

All porsches were air cooled up through 96 until the boxter came out in what i beleive was 97 from that point on all of the porsches since then have been liquid cooled.

just a bit o knowledge cause knowledge is power.

oh i used to work for porsche. Cause i dint honestly knwo that until i worked with them every day.

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http://cgi.ebay.com/ebaymotors/PORS...tegoryZ33617QQihZ016QQitemZ260014517862QQrdZ1

http://vista.pca.org/stl/911car84.htm

I stand by what i said... some of the old "air cooled porsches" used oil coolers.

I did some research on oil coolers and decided against one because I don't think my stock pump will put out enough pressure to run a cooler and I don't want to have to drop the pan just to install a hi flow pump.

cklaus said:

I think some of the older porsches that where predominantly "aircooled" had oil coolers to help cool the motor too ( i'm running on hear-say from stuff i heard years ago on that).

Click to expand...

I used to build air-cooled Formula Vee race motors and high performance VW dune buggy motors, along with the occasional Porsche. The effect of oil coolers is slight. If your oil temperatures threaten to rise above 250 degrees, you need an oil cooler, other than that, they're useless; especially on a liquid cooled motor.

I dont think you will need one, I had one on my gmc 4.3 motor and just took it off because the lines were so leaky and the replacments leaked, so I did away with it and mounted the oil filter right to the block and it has made no difference in regular DD operation.