Oil in the air cleaner?

[64R]

This is probably a stupid question. I'm rebuilding the 425 in my 64 and while I'm at it cleaning up and painting anything that attaches to it. When I took the filter out of the air cleaner I noticed about a 1/2 cup of oil in there. Does this have a purpose, I seem to remember oil bath type filters from many years before but I thought that ship had sailed?

[CheezeMan]

On other cars, if you put too much oil in the engine, the excess shows up in the air cleaner (comes through the breather or pcv valve). I don't believe there is any valid reason to pour oil in the air cleaner.

On my '63, just about any fluid that has too much in the container will burp out somewhere the excess. you may want to check your oil level first.

When I first bought my car, I noticed that the triangular bottle for windshield solvent had transmission fluid (red) in it. that is the same fluid used for the power steering. I also noticed that the power steering pump was leaking and sprayed all over my insulation and everywhere else on the side of the engine bay. it was ugly and thick!! Apparently had been going on a long time. So, dutifully, I kept adding extra fluid to maintain it. What I didn't realize was that IT WAS TOO FULL to begin with!!! It kept burping out the excess. When I finally drained some out, it stopped leaking!!!

Check fluid levels and make sure they are on the mark.

Good Luck

[JZRIV]

Rob,

Not a stupid question at all and your assumption is correct, that oil is not supposed to be there.

Does your air cleaner have a connection to the valve cover for closed crankcase ventilation system? I think the closed PCV system started sometime in 64 for California cars so the possibility exists thats what you have.

The diffierence between an open and closed PCV system is on an open system (non CA cars)the oil cap is vented with a mesh screen. Ventilation air is drawn into the engine through the cap, through the crankcase up through the PCV valve and into the intake manifold.

On a closed system (CA cars) the oil cap is not vented and air is drawn into the engine from the air cleaner housing then into the crankcase through a tube connected to the valve cover.

When internal engine wear progresses to the point where there is more blow-by from the combustion chamber than the PCV system can handle, it becomes overwhelmed and flow reverses blowing polluted air out the oil cap on an open system, or back into the air cleaner on a closed system so it can be sucked back into the engine and burned off instead of spewing it into the atmosphere. During that process, oil vapor moves with the blow-by and settles in the air cleaner housing which sounds like what you have. Excess blow-by can be caused by worn piston rings and/or valve seats.

Having said all that, if your car does not have a closed system with a connection between the air cleaner and valve cover, the above info is meaningless. No clue how the oil got there. But if it does, you either have a defective PCV valve or excessive internal engine wear with the latter being more likely.....unfortunately.

Edited March 4, 2011 by JZRIV (see edit history)

[64R]

Thanks for the reply Chuck, it seemed kind of odd to me but I couldn't figure out how else it could have got there? The air filter itself is certainly not what you buy these days either so that just added to my confusion.

Cheers

[64R]

You just posted at the same time as me Jason, everything is all apart but my recollection is there isn't anything going on between air cleaner and valve cover. I know I have the mesh screen type breather as it was always smoking, hence the rebuild, well that and well over 100,000 miles on it.

Now here's an interesting thought, and also a confession. As it was smoking out the breather, I put a cap on it from a 64 small block nailhead that my son had figuring that maybe it wasn't a must, I drove it for 10 minutes or so and came back, the engine pressurized and gushed oil out through the dip stick hole, leaving a good size puddle. Perhaps it gushed back through the carb as well?

As embarrassed as I am to admit this maybe someone will benefit from it and either way I was rebuilding the engine.

[RivNut]

One thing to check on is to make sure that the splash shields are in place (or the proper place) under the valve cover. The shields keep the liquid in the engine but lets the fumes escape. The shields bolt on the top of the rocker assembly directly under the PVC outlet on the passenger side and under the filler cap/breather on the driver's side.

Ed

Edited March 4, 2011 by RivNut (see edit history)

[Guest]

This is probably a stupid question. I'm rebuilding the 425 in my 64 and while I'm at it cleaning up and painting anything that attaches to it. When I took the filter out of the air cleaner I noticed about a 1/2 cup of oil in there. Does this have a purpose, I seem to remember oil bath type filters from many years before but I thought that ship had sailed?

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Under heavy load or max load full throttle conditions, the manifold vacuum is insufficient to draw blow-by gasses through the PCV valve, and therefore blow-by flow goes through the tube-to-air cleaner in the reverse direction. In cars having excessively high blow-by, some of the flow will go through the tube connection to the carburetor air cleaner. This closed type system was designed because the first systems ( like type "A" PCV ) when under full throttle or heavy load would reverse flow out through the breather and into atmosphere.

Does the oil in the air cleaner have a purpose? No, it just indicates the engine has a lot of blow-by. Today's engines are still the closed type, the PVC valve is located on the intake manifold and the tube to ventilate fresh air to the crankcase is on the filtered side of the air filter via tube to a valve cover .

Don

Edited March 4, 2011 by helfen (see edit history)

[64R]

Thanks guys, the engine was pretty clean so the splash shields should be fine, it just smoked like crazy out the breather which would then vent into the cabin. The rings were no doubt toast so lots of blow-by, it had 125,000 miles or 225,000 for all I know on it. The block is at the machine shop and parts are on the way.

As usual I learn something new from you guys, thanks

[JZRIV]

Thanks guys, the engine was pretty clean so the splash shields should be fine, it just smoked like crazy out the breather which would then vent into the cabin. The rings were no doubt toast so lots of blow-by, it had 125,000 miles or 225,000 for all I know on it. The block is at the machine shop and parts are on the way.

As usual I learn something new from you guys, thanks

If it was blowing by that much, the oil vapor was being sucked into the air cleaner inlet where it would collect on the filter and pool under it.

Good Luck with your rebuild. Do you know what camshaft will be installed?

[64R]

Good Luck with your rebuild. Do you know what camshaft will be installed?

Thanks. I believe it's just a stock replacement cam which is fine with me