Pumping oil!

[Mitch]

Well I hope someone can figure this out. 1988 YJ Wrangler with 4.2. Motor runs great (only 122HP) but I get 1 oz. of oil up in the air cleaner housing every trip I take. The front pvc valve has been replaced and works fine, but the back opening on the valve cover is a different size open tube without a pvc valve that goes up into the air box. I've switched to a K&N filter that I can clean every other ride but this stinks. Then amount of oil will compleately plug a paper air fiter in 3 rides and it must be tossed out. Help!

Mitch - great88

[Mike]

I had a 92 YJ a few years ago and I had a similar problem. I got sick of changing air filters. I went shopping at the auto parts store until I found a filtered joint that, after some careful alterations to the plastic, would fit the valve cover opening and allow the recirculation tube to attach. After that the problem stopped. I couldn't find a stock item. The only filter I could find had to be altered to fit.

Other folks may have better answers....

[Mitch]

Thanks Michael,

At this point anything will help. I've been cutting strips of cloth towels and stuffing them next to the filtered inlet where the oil is coming up from and then replacing those on a per drive basis. I did not originally mention, my oil pressure gauge reads 80lb or is pegged (100lbs?) most of the time.

Mitch - great88

[aston]

Thanks Michael,

At this point anything will help. I've been cutting strips of cloth towels and stuffing them next to the filtered inlet where the oil is coming up from and then replacing those on a per drive basis. I did not originally mention, my oil pressure gauge reads 80lb or is pegged (100lbs?) most of the time.

Mitch - great88

I suspect the high oil pressure is a factor. The pump incorporates a pressure relief valve that is supposed to limit maximum pressure to 75psi. Maybe an oil gallery is blocked. If the pressure is high in one circuit it might be dangerously low in another.

[Kodiak Spirit]

or you have a valve leaking by that is blowing into the valve cover and sending oil out the in.... I get oil in my aircleaner as well, and I am thinking a valve job is in order. getting ready to do a poor mans engine rebuild this summer... I also got a cracked exhaust manifold.

[aston]

or you have a valve leaking by that is blowing into the valve cover and sending oil out the in.... I get oil in my aircleaner as well, and I am thinking a valve job is in order. getting ready to do a poor mans engine rebuild this summer... I also got a cracked exhaust manifold.

Sounds plausible...a compression test will quickly find a leaky valve.

This would not account for the high oil pressure.

[Mitch]

Thanks for the sugestions. Because the engine runs so smooth and strong with no smoking at all, I'm thinking that it is not a valve/compression issue.

Mitch / great88

[Russ Chung]

Thanks for the sugestions. Because the engine runs so smooth and strong with no smoking at all, I'm thinking that it is not a valve/compression issue.

Mitch / great88

I think that Jesse (Kodiak Spirit) meant a leaking valve stem seal NOT the valve itself; if the valve leaked, your engine would run rough and your compression would be bad, but if the valve stem seal on an exhaust valve were to leak, then engine exhaust could get into the valve cover area and increase the amount of blow by. This would occur at high power and would be vented through the air intake. I believe that blow by that occurs during idle is vented to the intake manifold through the PCV valve, but at high power, it is vented through the air intake, thus contaminating your air filter. I cannot think of an easy way to test this; maybe you can take the valve cover off and look for exhaust leaking past the valve stem seals with the engine running?

[aston]

I think that Jesse (Kodiak Spirit) meant a leaking valve stem seal NOT the valve itself; blah........past the valve stem seals with the engine running?

Hey Russ, good point.

If the valve stem seals are leaking, sometimes you get a cloud of white smoke first start in the morning, 'cos the oil leaks down into the inlet/exhaust overnight. When this oil has burnt off everything returns to normal.

[Kodiak Spirit]

yeah, thats what I was thinking the valve seal. I have wanted to test it, but it's gonna be a bit messy to do that, specially if it is leaking

[Mitch]

I think the first thing that I'll do is replace the oil pump and see why there is so much oil pressure. I was not aware of the relief valve situation (75lbs max). That has to help somewhere. I've heard that removing the valve cover on an 1988 4.2 is a pain and local shops want 4 hours labor just to replace the valve cover gasket!
Thank you to everyone for your help and ideas. What an awesome group of people.

Mitch - great88

[FromLadaToJeep]

Hey there... I just purchased my first Jeep. 91 YJ 2.5 and it has oil in the air cleaner as well.. Im am just curious.. how would you define a "poor man's engine rebuild"? Cause I'm not quite rich and I may need to do one.
Thanks

[Kodiak Spirit]

Basiclly the poor mans rebuild is you don't take the engine out of the vehicle.
You drop the pan, pull off the head, send the head in to be rebuilt, pull the pistons, flex hone the cylinders, mic the cylinders and buy new rings to match the gap... new pistons if you need them.
Mic the crank and get new bearings for that if you need them and then put it all back together.
Its not really hard to do, just takes some time. usually when you do the head, you can figure on doing a new exhaust manifold, because it is right there, and everythings apart allready. and if you want to do a clutch and flywheel that would be the time... don't forget a new throwout bearing. and you might want to do the clutch cylinder as well. the real reason its a poor mans rebuild is that you are not paying another guy to do anything but the head work, but the head is where most of the problems are anyways. The drawback, is that sometimes it can be hard to get a real good seal on the block with a rebuilt head and an old block, usually the "shop" will give the block a quick re-surface and the poor mans rebuid skipps that step. it is still not cheap, and if you find real problems, then it can get bad, but at least your not finding them on the trail...