Thanks for the replies everyone...good to know there is no thermostatic valve...if i can find a cheap in-line one (doubtful) i will try to add it in... Going to go with a universal oil cooler from Summit Racing...for a new cooler and lines its about the same price as used cooler and lines off a 4.0...new is always nicer...

I will follow-up with an update on operating conditions. I should be getting my soft spring thermostat in the mail any day... so we will see what that does to the oil temps and then with the added cooler.

 

Update:

I installed a used oil cooler and lines from a 4.0, bolted right on. Had to essentially release the radiator from the front so that the radiator could be pushed back toward the fan and the cooler could be dropped in. Really not a bad job...the biggest pain was routing the cooler lines...they have to go in exactly the right place or they wont slide in allowing the nut to be tightened...couldn't find a good diagram in the RAVE but managed to get them on...took about the same time as installing the cooler.

So far not too impressed with the results... I just got it in last night and went for a cruise, oil temp went up to 200-204F with the outside air around 80F, cruising on the highway 60-65 AC off.

This morning was a little better 176-180 with outside air around 70F and traveling slightly slower.

I was shocked to see it get above 200 last night...i really expected it to make a huge difference...and ideally i want my oil around 180...

I need to gather some more data but am i missing something here?

Anyone have oil temp numbers to compare?

Prior to installing Oil Cooler:

Before Thermostat Mod (outside around 90-95F):
Idle - ~200F Oil Temp
Highway - ~220F

After Thermostat Mod (Outside 95-100F):
Idle - ~180
Highway - ~220F

 

Why the huge concern with the engine oil temp?
Are you having sludge issues?
I think the biggest difference would be while offroading.

 

Hey Spike,

The concern all started when I installed a oil pressure and temperature sensors via the glowshift sandwich oil filter adapter. The oil temperature would consistantly be over 200F and anytime it was over 90F the temperature would go up to 220F. I even hit 240 when it was hot and climbing a long hill (highway).

I always thought you wanted to keep your oil around 180F and after some research I discovered that all 4.6s didnt come with an oil cooler...which i still havent heard a reason why they would delete it...so i figured it would be a good idea to put a cooler in.

Havent had any issues with the truck.

While off-roading i stay around 180-190F.

I can't find any oil temps to compare to..everything i see is for coolant. I will be borrowing a scanner tomorrow and comparing my oil to coolant temps.

 

Just thought of this...

If my oil temperature sensor is located before the oil cooler than i would be reading the same or close to the same temps as before since the oil hasn't had time to pass through the cooler.

If the sensor was located after the cooler i would be seeing cooler temperatures. So COOLER oil has to be going someplace!

I could scan the inlet and outlet pipes with an infrared gun to see what the difference is...this obviously would be acurate temp but would give me a good feeling if there noticable difference.

 

They deleted the oil cooler because it was no longer needed after much research.
90% of the SUV's sold in the US never leave the pavement, Land Rovers included so to save money it was deleted.
It was deleted in the 2001? model year along with the CDL.
Of course this did not lower the price of the truck.

I have no comparison numbers to give you other than from auto school we were taught that internal (crank case) temps over 400*F the oil will stop lubricating and around 450 the engine will seize.

We were also taught that todays (mind you over 20 yrs ago now) smaller engines work harder and run at higher RPM so using a high quality engine oil and changing it per manufactures recommended schedule was a must.

Engine oils are better now than they were 20 years ago.

I honestly dont think you need a engine oil cooler unless you are towing heavy trailers all the time or offroading all the time.
Does it hurt to have one? No. Not at all.

I would not worry about your engine oil temps.

That is all I have to offer on this, take it as you will.
I wish I had comparison numbers to give you.

 

see ELEPHANT RACING Tech Topic, Oil Temperature and Engine Life Oil temp as a rule of thumb is about 10 - 15 degrees above coolant, and takes longer to get to that temp than the coolant. So your gauges should not increase at same rate, coolant will reach thermostat threshold before oil temps get there..

 

And the chart proves what I've been saying all along, use Shell Rotella 15w-40 because it can stand up to the heat.

 

Thanks for the feedback and reassuarnce.

I like the last line in the article:

"Equipping your car with an external oil cooler will help ensure long life."

 

Just keep in mind repeated short trips that do not let the engine oil get up to temp will also shorten the engines life.

I have this problem with my wifes car in the winter time, it gets water in the oil because it does not run long enough to get the oil to temp.
The battery will also get weak and need to be recharged once a week.