High Oil Pressure and Oil Leak.

[fedrusion]

Went out to wispering pines on saturday and had a pretty good day. On the way home I noticed that my oil pressure seemed higher than normal, idle was about 50-60 and under load was about 60-70. This was also once it was hot, it has typically been about 40 once its warmed up and under power, and about 25-30 at idle. I know the sending unit on these are known to be troublesome.

Besides the high oil pressure I also seem to have developed a leak, it appears to be coming from under the inspection cover on the tranny bell housing. Ive checked to make sure I dont have a leak from the head or valve cover that is runiing down the back side of the motor so I am reasonably sure it is the rear main seal or the oil pan or both. I wasnt to worried at first since it was only a small amount of oil but after driving around on sunday similar distances to saturday, it is much worse than I originally expected and needs fixed soon.

Does my prognosis sound resonable, I find it very coincidental that I have both high oil pressure and an oil leak however high oil pressure shouldnt cause a rear main leak as far as I know.

Any ideas. seems to be too much of a coinicidence 4 wheeling, high pressure, oil leak.

Also its a 4.0 with about 70K miles, I believe mostly city driving before I got it.

[fasteddie]

high oil psi could cause the leak if the seal was weak to begin with i\'d be willing to bet on the rear main leak however the leak would not cause the high oil psi  the cause of the increase in psi needs to be found possibly a restiction or pluged pcv which would increase case psi in general

[fedrusion]

One of the first things I checked was to remove the PCV completely so the valve cover was effectively open, made no difference in oil pressure. I\'m going to bring a mechanical gage home so I can check to make sure the sender is working properly.

[gCracker]

I have seen some engines, in my Chevy truck for example, that when the oil level gets low the pressure increases.  Have you checked the level?

[fedrusion]

Verified my oil pressure sender is reading correctly, reads right with the mechanical gage but slightly more stable. Now to figure out why the sudden change in pressure. I\'ll be able to work on it saturday at my dad\'s shop so I\'ll see then. Double checked my pressures when warm under idle and load, 50psi idle and 60 psi under load. Not terribly high, just interesting that there was a sudden change.

Checked the oil level as soon as I noticed the leak and it was about halfway between the safe and full line.

[GTJake]

i know i probably already asked this, but do you have a pic of your truck? im intrested to see how it sits w/ the rustys lift on it.
that came with an entire new rear leaf pack right?

[fedrusion]

There are a couple pictures I posted in my first post:
http://www.mudnuts.org/modules/newbb/viewtopic.php?topic_id=535&forum=2&post_id=3493#forumpost3493
There is also a link I posted from WP when I went in the spring. I cant go to photobucket from work otherwise I would find the good ones for you and post them.

It is the Full rear springs in the kit, I got the 180lbs/in springs which sit a little higher at about 4 inches after a year.

[fedrusion]

All Done, Started tearing it down and it looks like it was only the rear portion of the pan gasket that was leaking, Since the seal was cheap and I was already in there I swapped the rear main. All back together now and no leaks.

New filter and oil and my oil pressure is the same. Although not out of the ordinary for what it has had in the past with a fresh oil change. No Worries.

Thanks for the help.

[GTJake]

sounds like it was an EZ fix. good thing you cought it in time