What causes it to leak oil?

On my 1948 Chevy Fleetmaster's original 216ci engine, there is a vent tube on the right side of block that extends past the bottom of the block. While the engine is running there is a constant drip of oil coming out of it. It will actually puddle if it is in the same spot for a couple of minutes. What causes this? How can I fix it? Thank you in advance for any help you can offer.

 

The vent tube is to allow the pressure inside the engine to escape. Since you are leaking oil it means there is a lot of blowby from worn out rings and the oil is coming out with the fumes. You need to do a compression test or leakdown test and see what condition it is in.

You didn't say how many miles were on it but you are probably looking at a rebuild or replacement.

 

Sorry! I should have included more info.

The car has 45,000 original miles. My family has owned the car since 1981. It runs flawlessly. It sat stored in dry polebarn from 1981 until 2008. With maybe only 1000 miles being put on in this almost 30 years.

 

Is the oil in the engine been in there for years? If so change it. You may be seeing contamination ,water-fuel, being cooked off from the heat of the running engine. With that much driping you should be seeing lots of blow by smoke if the rings are stuck/sticky. More info needed.

 

Because it sat so long, you might have a stuck ring. Try some Marvel Mystery oil, you might be able to "unstick" it.

 

How many aftermarket or replacement miles on top of that?

Do a compression test- that's blow by. These cars had no PCV system. If you rebuild the motor, try to include one

 

Or, it could be British.

 

It's traditional,... old school technology, what happened before PCV systems.

 

This might be an obvious question, but how do you include a pcv system in a motor? I'm refreshing a 235 and I'd like to do that! I did not know that was possible, but maybe that's because I don't really know how it works

 

If we don't drop oil, what are we going to do in the future?
When, there are no oil deposits to find?
Think about it.
...

 

Putting a PCV valve on your car is really not traditional.
It's not what was done in the 20s, 30s, 40s, 50s.
It might just get you kicked off of the HAMB.

 

Sad, but true. I got locked in a battle-royale with a "traditionalist" a few nights ago, and the thread got locked. I like messing with those guys, but they get way too sensitive.

 

Its a Chevy, they leak oil its just what they do. Me I put a rug in the garage and bam problem solved. ( or more easily ignored, you get the idea)

 

If you're interested in doing the PCV thing, here ya go.

http://www.speedprint.com/deves50/pcvinstall.php

But I will say all that will do with a lot of blowby is foul out your plugs and make the smoke come out the back end instead of the road draft tube. Like Flat-N-Low suggested, some Marvel or ATF in the cylinders may 'unstick' your rings. You may also just have to tear it down & re-ring it. Not a huge hassle or expense on these cars.

Good luck!

 

Have had good results in the past pouring a quart of tranny fluid in, the driving car 10-15 minutes so that it goes thru a couple of heat cycles. Then doing a complete oil and filter change. Do it while its still warm as either Marvel or tranny fluid will loosen a lot of junk in the bottom end and you'll want it to drain out rather than giving it a chance to settle back in the pan. And don't cheap out and not replace the filter.

 

Some expensive cars had PCV valves in the 1920s.