ford lehmin oil leak from air intake

[chuckg5]

we have an older rebuilt 3 years ago Ford Lehman 65Hp. problem is, oil leaks out of the side air intake filters and drips into the bilge. the engine has a hose from the oil cap to the air filters. I guess the splatting oil is suppose tobe sucked back into the engine with the air but the bottom of the sponge air filter is soaked with oil. Can I just bend the rubber tube coming from the oil cap back an stop the 'flow'? Do other engines do this?

[Faster]

That would be your crankcase vent.. if you plug it you may pressurize the crankcase and have more problems, esp if you're experiencing some blowby (possible if the vent is passing a lot of oil) Pressurizing the case could cause seals that are not leaking now to do so....

Can you reroute the hose to another area in the air cleaner/intake that will more likely 'suck' the drippings back into the engine?

[chuckg5]

great suggestion. I'm going down to her tommorow an will look to see if I can tube it further into the air intake.
thanks again!
chuck

[Stevewlf]

I've seen that problem in cars that had a crankcase vent hose coming off the valve cover. Pressure in the crankcase from ring blow by would be the first concusion. However, in my instance, it only happened after running at high RPM for 30min or so. Turned out that the oil being pumped into the oil passage in the valve train assembly was coming in faster than it could flow back to the crank case. In my case, the head gasket holes where the oil should drain back were under size (or had collected sludge) so I just cleared them out with a flat blade screw driver. Another possible cause, there might be an oil restrictor in the oil passage going to the head and that might have been left out when the engine was rebuilt. I've seen this in some auto engines and later found it in the bottom of the parts cleaner tank.

Anyhow, you can verify if you do have an oil flow back problem by carefully pulling the oil cap just after you come off an extended high RPM. To avoid hot oil spray, idle down and take a quick look inside and see if you see a flood of oil inside. The valve gear should be just wet with oil and only small pools in the recesses of the head and around the valves.

To cure the problem, take off the valve cover and probe the oil drain back holes for obstructions. If an oil restrictor is missing, then you will have to wait until the next top end overhaul.

My opinion, FWIW.

Steve

[MacGyverRI]

see if the hose has a downwards loop that catches the oil and try to make it more uphill if that's the case.

Also look for other breathers and clean them out as they may be causing more back pressure that is pushing it to the air cleaner.

If you have way too much blow by, it may need a rebuild again.

[chuckg5]

Hi, an thanks
I like the idea of putting on a longer tube an loop it higher up in the engine room before going to the air intake. I'll try that this weekend. chuck:

[MARC2012]

Longer hose, catch in container.Seen this done on larger engines.Not a fix but less mess.marc

[Capt Len]

The injector return line is inside the valve cover on that model ??? If a washer or soldered fitting should fail, fuel goes into the lube oil .This is not good as you can guess. I've seen several run away by sucking oil into air intake when level in sump increases. If your injectors are outside the cover Ignore this info.

[chuck53]

If you ever have problems with Lehmans, call American Diesel in Kilmarnock, VA and if you are lucky to get Bob Smith on the phone, you have reached the one person who knows more about Lehmans than anyone.
He can diagnose and tell you how to resolve problems over the phone better than most mechanics can sitting in your engine room.
This guy is basically the father of the marinized Ford Lehman.

[chuckg5]

I buy parts from him quite abit. Next are engine mounts.
my model has the injectors on the outside of the valve cover, thankfully.