Leaking oil filler cap

[brackie1]

I continue to have a problem with my oil filler cap leaking on my 77 spider. I replaced the old one with a brand new one and it quit leaking. I took it off the other day and put it back on and it allowed almost 1/2 quart to blow out while I was driving. I cleaned it up and put layer of thin rubber under the the one already there. It fit nice tight but still leaks a trace. Any ideas on how to keep it from leaking.

[baltobernie]

Are you leaking oil anywhere else; dipstick, cam housing, etc.?

[brackie1]

I did have a small leak at the base of the dip stick tube which I fixed. no leaks around the cam covers. My only other leak is the rear seal but not major. When I had the major leak it was all on top of the engine. As I said after I cleaned it up and put another layer of rubber in the oil filler cap it quit leaking except for a slight leak. When it leaks there is a small amount of oil laying on top of the cam cover and rolling down into some of the crevices near the front most spark plug. It just seems that the cap isn't sealing properly. It is a cap that I got from one of the fiat parts house. I wonder if some caps are better than others.

Gene
North Carolina

[baltobernie]

It sounds like you don't have a crankcase ventilation problem; that's good news.

I guess there are different manufacturers of the filler caps that will fit the Spider, and it's possible that somebody sold you either a defective one, or the wrong cap for your car. But if you bought it from one of the regulars seen on this forum, that's unlikely.

Is the surface of the cam box .... the mating area where the filler cap seats .... flat, smooth and unpainted?

[brackie1]

the oil filler hole is flat and smooth. I drove it today and a leak developed at the base of my distributor. I took it loose and made a new gasket and it quit leaking. Last year I replaced the original carb with a new weber DEFV it has a smaller air canister than the original one and I wonder if the carb is pulling enough of the crankcase pressure. After fixing the distributor leak I pulled the crankcase hose loose from the carb and let it vent into the atmosphere. drove it for about 30 miles and did not see any leaks. I have always wondered if there was not enough crankcase pressure being released.

Gene
North Carolina