I just picked up a 1957 Ford F250 from an auction and the first thing I noticed is its burning oil. Haven't had the chance to do a compression test just yet, plan to tomorrow. I find it weird there is no smoke coming from the exhaust, but coming from the oil fill cap. It's a very small amount but burning oil is a concern to me. My real question is, will this be something a new seal for something will likely fix? or am I looking at a whole motor rebuild? I'm curious to know because I didn't plant to keep the stock motor anyways, but wasn't planning on swapping it until further down the road.

 

Howdy,


Welcome aboard!

A small amount of oil "smoke" from the filler cap is quite normal but excessive "smoke" (or vapor) could be a sign of excessive blowby.

The only way you'll know you're 'burning' oil will be to drive it a few thousand miles and observe the oil level (and, of course account for any leakage too)

Although a compression check will tell you how much compression each cyl has, It won't necessarily tell you how much oil to expect to "burn"

Also, a good indication of engine cyl "health" will also include a leakdown check.


If you plan to run the engine for a while, remove the valve covers and ensure that each rocker has fresh oil around it indicating that there's flow to the rocker tube and rockers.......

Regards,


Rick

 

Yes, if you have the road draft tube system a small amount of smoke will sometimes exit through the oil filler since it is open to the atmosphere. It's not a cause for concern. A vacuum gauge would be another way to determine engine health.

 

The motor runs good. The compression test and the leakdown test showed the motor is in good shape. According the odometer(not entirely sure it works) it only has 98k on it. The issue is it doesn't always burn oil but when it does it doesn't stop it just keeps burning until its shut off. Also not sure its going to get a few thousand miles in its current state, brakes and clutch are almost shot

 

Most older engines I've been around, ones before cats, when they burnt oil, there was smoke from the tail pipe.

 

If you have good compression and leak-down, with little or no exhaust smoke, it's unlikely you're 'burning' a LOT of oil. You won't know until you can actually measure the consumption.

If the "smoke" bothers you, you might consider removing the road-draft tube and installing a PCV valve.

Regards,


Rick