Outer Limits 4x4 Board

does the engine oil need to be a certain opperating temp or does it not matter. Would i benefit if oil temp was cooler than standard.
The 3.9l has oil cooling threough radiator, am thinking of using a tranny cooler and bypassing the radiator, do you think that the tranny cooler would keep the oil cooler than the radiator??
Could i just join the pipes together and ignore the oil cooling all together, is the oil cooling actually oil heating for the snow??

I'm trying to decifer your post. you want to run engine oil through the trans cooler and just loop the line's for the auto?

for the effort and added risk of cooking the auto and different oil lines etc to blow I cannot see the reason for doing this unless the motor is a highly stressed race motor .

still pretty unsure of what your actually asking.

The TDI engine oils has a cooler in the radiator, just like on a auto.
had to work it out the first time I sore it on my 5 speed manual.
you can put your engine oils through a (trany) type cooler, but these is the risk of more oil lines braking

shakes wrote:I'm trying to decifer your post. you want to run engine oil through the trans cooler and just loop the line's for the auto?

for the effort and added risk of cooking the auto and different oil lines etc to blow I cannot see the reason for doing this unless the motor is a highly stressed race motor .

still pretty unsure of what your actually asking.

My radiator for my auto 95 disco is stuffed and to re-core it is $750 to $800. I don't have that coin lying around at the moment to do that, the vehicle i have had for nearly 6 months and have only had it out twice due to the over heating problem, have done some mods and am approx $8000.00 into it.
I have wrecking disco whick is part of the $8000 i have spent, with what i think is a good radiator however it is a manual 3.5l so doesn't have the engine oil cooling or the tranny cooler in and out of the radiator. Am desprate to get this vehicle into the bush where it belongs.

Yes, engine oil engine oil temp is just as critical as water temp, too hot and things start to go pear shaped, too cold and it costs you power/torque and potential wear, as a lot of the additives are heat activated.
If the car has an oil cooler standard, the oil temp is regulated by a thermostat, just like the water temp.

You can use a separate air cooled oil cooler for the engine oil, but how you'd size it I really don't know, and proper engine oil coolers aren't cheap.
I'm guessing a tranny cooler may be a bit too restrictive as an xw-40 engine oil is twice as thick @ 100* than an ATF.

The best oil coolers that I know of are made by companies like Setrab and Earls.
It'd be cheaper to get the correct radiator rebuilt.

In practical terms I think you would be OK with a 3.9 with no engine oil cooler.
I once drove 1950Km in Saudi in a 3.5 RRC at 50+c ambient , with both water and oil temps pegged. I used about 2 litres of oil ( shell Helix 20-50)but on a later engine stripdown there was no serious damage. And this was in 1985 when oils were nowhere near as good.
Just change it regularly and use good oil eg semi sythetic. A 3.9 is only a 3.5 with bigger holes, and there is no oil thermostat. the Radiator water temp warms it.

For the trans cooler you could get one of the coolers from a 3.5 which sits in front of the rad.
But the best is to get a new core ,as the Disco one is probably cactus by now.
Regards Philip A

IICR the Aquarangie (93 Vogue) ran the trans cooler through the rad and then with a cooler up front as well like earlier models 9like my current 87 hi-Line), is this is what you're asking, to bypass the line that runs through the rad?

I never had a trans oil problem when I had that Rangie, can't see the point of bypassing it. I am in QLD after all so any sort of cooling assistnce is wanted regardless.

Trav

armbrup wrote: <snip> and there is no oil thermostat. the Radiator water temp warms it.

<snip>.
Regards Philip A

really ?
the diesels use a t/stat, it's in the filter housing.

thanks guys for all your input, decided not to mess with it and just got the radiator re-cored $700. Picked it up after work thursday before easter and went to fit thursday to find the ideaots welded the mounts in the wrong place, had to modify.