engine oil leaking out of air intake

chuckg5 · #1 10-09-2010

does anyone else have this problem?: I have an older 65hp ford lehman that was rebuilt totally last year. it has two air intakes on the side of the engine and has two thin round air filters wrapped in thin foam around the metal frame of the intake. the bottom drips oil, engine oil. its soaked but I don't see the physical dripping of oil except its in my bilge water. maybe because its side mounted that this is the problem.

Faster · #2 10-09-2010

Do you have hoses running from the valve cover to the filter cannisters? They usually come from a PCV valve and the intention is that the engine aspirates any oil vapours from the crankcase.

In some cases an excess of oil will travel this path and be evidenced by what you're seeing. However that's usually on older engines that are suffering from "blowby" that tends to pressurize the crankcase and force more oil out those hoses. With a freshly rebuilt engine (assuming a proper job) that shouldn't be happening.

chuckg5 · #3 10-09-2010

Yes, Faster
it does have those hoses and that is where the oil is coming from. should i block those hoses off? or will that cause more problems.

chuckg5 · #4 10-10-2010

can those pvc hoses be blocked off or will that cause more problems?

erps · #5 10-10-2010

Don't block it off but you may need to wring out the circular sponge filter more often.

chuckg5 · #6 10-10-2010

OK, thanks, erip - I forgot the right name

Faster · #7 10-10-2010

No you shouldn't block them off... they are how the gradual buildup of gases and pressure in the crankcase are relieved. The idea is the suction from the air intake puts the vapours back through the combustion side of the engine.

Blocking them off will eventually allow that pressure to build, resulting in leaking seals, oil coming out the dipstick tube and any other way it might find.. making a mess of the engine space..

Here's an interesting discussion on Wikipedia: (I doubt these engines have an actual 'PCV valve)

PCV valve - Wikipedia, the free encyclopedia

There's mention here of an "oil trap" that might be installed between the valve cover and the connection to the breather. Food for thought....

erps · #8 10-11-2010

Quote:

There's mention here of an "oil trap" that might be installed between the valve cover and the connection to the breather. Food for thought....

A fellow over on the C-34 owners website shows pictures of a home made trap he made. IIRC, it was basically a canister made out of a couple of cans with hose fittings at either end with foam rubber in the middle.

chuckg5 · #9 10-11-2010

Both, good suggestions.
I'll follow up on this
Many thanks!
chuck

CrazyRu · #10 10-11-2010

Is it possible to vent the lines into fuel tank? I don't see why it can not be done. Just an idea...