YJ 4.2 Mystery Oil Leak

[c.walston]

Need some Help!!!!!!!! I got a 90 YJ 4.2 ltr. that has a mystery oil leak....after I drive on the road for about 15-20 min the pass. side of the eng comp is covered in oil...covering from the fuel pump to the tranny.

I have already changed my distributor seal, oil filter, tightend my oil pan and valve cover...is there anything else on that side that could be leaking that I just can't see because of all of the oil?

I do have a valve cover leak as well but it isn't leaking enough to cause this leak...I also tried loading the eng @ 2500 rpm for 10 min in the garage to see if I could spot the leak and nothing...but as soon as I get her on the road...there she goes again!

Any assistatance would be great!
Chris

[RescueJP]

could it be blow bye possibly. Man its a 4.2 it aint a mystery its a monster lol. I fix one leak 2 days later get a new one so on and so on

[mousee]

worry when it QUITS leaking!
Check yer oil pressure sender. also check yer timing cover.
Mine will leak down to a quart low and quit leaking. If I add, it will leak it right back out, if I leave it, it will stay there... figure THAT out! lol

[sadass]

[quote=mousee;66459]worry when it QUITS leaking!
That is a good one, I am going to remember that.
I second checking the oil pressure sending unit .

[c.walston]

Thanx for the info so far...I will try to see if letting it run a quart low will work for now...if not I will keep on adding oil to her until I can get under her and check the oil pressure sender...working 12's is a pain!!!!!!!!!!!
chris

[CrazyHorse6]

Check your PCV valve - does it still rattle? If not you may be getting blow by, coupled with the wind from driving its spraying the leak all over the place. Also check to see if its leaking out of the dipstick.

[RescueJP]

ooooooo mine is leakin out the oil breather only at speeds above 55

[c.walston]

I've got a new PCV valve...and no oil from the D-stick...I got new oil pan and valve cover gaskets I'm going to put on soon to help me try and narrow down where the leak is coming from...so we shall see...but it is definatly a good possiblity of blow-by...also let the oil run a little low and its not leaking as bad right now!
chris

[RescueJP]

what about me anyone anyideas on oil threw the oil breather at the back of the valve cover

[CrazyHorse6]

what about me anyone anyideas on oil threw the oil breather at the back of the valve cover

Remove your valve cover and thoroughly clean it out to ensure no deposits are clogging the PCV valve and the breather. If either are clogged, it can limit pressure from escaping and limit crankcase breathing. If you stilll have the problem after cleaning the valve cover, its probably blow-by from the piston rings.

Take a look at this link over to jeepforum which discusses your engine and similar problem.

Crazy