OK How does a bad lower intake gasket cause you to burn oil????? please help!

[Isaac]

Ok im lost here,, i have been reading so many posts on this board and i now and wondering and asking someone to please exsplain to me how exsactly a bad "Intake" gasket causes a losing oil conditoin??.
i recently bought a 92x and it to loses alot of oil "like a qaurt in only 400 mil's" smokes when revving with no load at higher speeds (3k or higher), and also has the very load ticking everyone has talked about. please give me some insite on this matter and how the lower intake when bad leaks "OIL" ?
all the intakes i have ever seen only have water passeges aside from the air. is the 4.0 different in some way?????
Thanx alot for any help given you guys!
Isaac

 

[mrboyle]

The lower intake serves three purposes. First it directs air to the cylinders, its next purpose it to bridge the cooling passage between the sides of the engine and finally it serves as a way to seal the lifter valley. This is the large open space on thr top of the short block (bottom end) where the lifter bosses are located. The intake seals the oil in the valley from escaping either through the intake ports (intake gaskest seal this) or out either end of the block (silicone does this). The oil loss you describe could be one of two things. You are either pulling oil into the combustion chamber through the valve seals, or from the valley into the intake runners. If the leak is due to the gaskets it can be repaired (replacing the intake gasket set) or if the guides are the problem, you will most likely need a valve job done on your X.

 

[Isaac]

ok great! Thank you!! (more)

Thank you for clearing that up, i didint even take notice to that lastweekend when i did the valve covers (they were leaking good and now are sealed very well and im still losing oil)
i will be changing the lower intake gasket nextweekend.
i take it the seals on this motor can be removed without removing the heads? using compressed air to hold the valves in place one at a time?.
Thanx again for the info! very helpfull!.

 

[mrboyle]

Re: ok great! Thank you!! (more)

Originally posted by Isaac
i take it the seals on this motor can be removed without removing the heads? using compressed air to hold the valves in place one at a time?.

If you are referring to the valve seals, I don't know of any reason why they can't be replaced in this mannor. I have never done this on a 4.0 so I can't give you a 100% guarentee that they can, but every OHV engine I have worked on before this was possible, so I don't see why the 4.0 would be any different.

 

[Isaac]

yep,, the valve stem seals.

Thanx again for your help,, yep the valve stem seals is what i was refering to.
i guess ill go ahead and do that to next weekend,, may as well while im in there.
thanx
Isaac