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GURU question?

mgreen84

NAXJA Forum User
Location
Georgia
What is the ideal temp. for maximum flow, lubricaton etc for motor oil?(I run Mobil 1) I have put a oil cooler on my xj, and due to other issues I took it off today.... I've heard good and bad about oil coolers...I knwo for certain if you tow alot of run really big tires and gears but for your everyday driver what is the opinion?
 
When I was racing bikes we shot for between 160 and 180 F. as the ideal. With 180 F being pretty much the magic number. In bikes the oil was also part of the cooling system, along with air cooling.
At summit and Jegs they used to offer thermostatic bypass valves to help keep a constant oil temperature.
Mobile1 flows well at very low temperatures, over cool oil shouldn't be much of an issue and would probably help with overall engine cooling.
Likely more of an issue with Dexron and the autotranny. At very low temperatures shifts get late and slow on a cold tranny.
With fossil oil, the lifters get noisy and stay noisy longer in very cold weather.
 
Thanks for the replies....the reason I asked is with my oil cooler I noticed the oil pressure of course ran higher than before (thicker oil)... with it off the pressure is a little lower when at full running temp. but the MPG is noticably better (strange...using GPS I get about 1.3 miles more to the gallon) and the engine is actually quieter on the top end without the cooler....I used a dipstick thermometer to get the temp of the oil after driving for nearly 2 hours with the cooler on and again yesterday with it off....suprisingly ther was only a 16 degree difference...does all of this seem correct?
 
There may be a restriction in the cooler system someplace. Funny I've never found anything better than grabbing the end of a hose or line and blowing through it, you can feel a restriction quick. Used this technique mostly on tranny coolers, but probably applicable to engine coolers also. I have on occasion found restrictions in various tranny cooler setups.
Air block may be a factor. If a bubble doesn't move, it eventually equalizes pressure with the shared medium (oil) and causes a restriction. It will eventually dissipate, but this takes awhile.
The 4.0 as near as I can figure from research (there isn't much info out there), oils from the top to the bottom. The cam gets oil first. If the top is noisy, this can be a sign the bottom of the motor may be oil starved.
 
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