In Reply to: Re: Oil fill tube has white foam posted by Tim on December 20, 2007 at 06:49:31:
I had this kind of a problem with my 1997 F-150 truck a few years ago. Oil filler cap was milky but when I changed oil all seemed OK, no milkiness or streaking. I also noticed that the radiator reservoir would slowly seep down over time; I would top it off and two or three weeks later it would be back down again. It developed that my truck had a factory defect that allowed coolant to seep into one of the cylinders through the intake manifold, where it would be burned and exhausted so it never got into the crankcase. Obviously in a Model A this can't be the case.
This problem is potentially serious, so I'd stay with it until you get it figured out.
My Dad suggests a couple of possibilities: a leak past the head gasket, or a small crack or pinhole in the block could let a small amount of water into the crankcase. It wouldn't necessarily take much to result in foaming action. Check your water level in the radiator, is it noticeably going down over time? If it's not on the floor it has to be going somewhere. If you are using permanent antifreeze, he suggests you should use straight water until you get the leak fixed as it is less likely to permanently ruin the engine (which antifreeze will do).