Ey guys I've been trying to track down my friggin oil leak for a few months now. I'm really tired of oil spraying every thing under the hood it's got to te point that if I don't degrease every now and then my starter quits. Here is the list of things I've replaced:
Valve cover gasket
Rear main seal
Oil pan gasket
Removed oil filter adapter
New sending unit
Distributer gasket
Pcv and ccv hoses are free and clear

Everything has been replaced with a fel pro gasket so theyre not cheap crap. It won't leak a low rpm or idle but will at highway speeds

Thanks in advance for all help.

 

Get some oil uv dye wash it add the dye it will glow orange if I'm right. That would be the easiest way to find the leak

 

I did that but it wouldnt show anywhere. It only leaks at high speeds, which at that point it blows it everywhere. Sooo I'm not too sure what else to do.

 

What do you mean you removed the oil filter adapter? So that now the filter screws right into the block?

 

Did you try revving it with the hood open? Make sure to wear a face shield lol.
Just slowly rev it to 2k and look around, have a buddy help so you can look under too. try not to rev it too long though.

 

only high speed? Is it gear oil from the front diff somehow...vent, axle seal, pinion?

 

Yes. It took me maybe 20 minutes, I was lucky as had a normal bolt head, took it off and took the nipple that the filter screwed on to and mounted that straight to the block and changed oil filter size

 

Wait til you go off-road and the mounts flex a bit. You think you've got an oil leak now?

 

done that 2x in my CJ-7 with the 258. I was pleasntly surprised when I saw they fixed that on the 4.0's.

 

Yep. Fooling yourself if you think it ain't gonna happen on a 4.0.....

 

Seems like a plan to me. I assume the leak is pressure related, so rev the motor to bring up the pressure and watch.

 

could be transmission fluid from the lines, also check your oil filter o ring. and more info would help where is the fluid under the hood driver, pass side? ect...

 

It's on the passenger side and it's for sure oil. I even figured out that if I took the angle of the dipstick top from there back got oil on it, nothing in front of it. So I think it's coming from the dipstick tube.

 

Is your ccv system plugged? Any oil in the air filter box?

eta: I see you stated the CCV hoses are clear. How about the orifice and rest of the system?

 

Quick question, what causes the oil to get into the air filter box? I've been having that issue.