That sounds like valve stem seals.
I had a 77 F 100 with a 460, after idling for a while when I took off it blew a lot of smoke for a while then it would stop.
I put new valve stem seals on and all was good. Before I bought the truck it had sat a while and I guess the seals dried out?

 

Thanks for all the replies. We're still trying to figure it out.

 

700 mile round trip and he used 10 quarts of oil! No smoke and no leaks, still puzzled.

 

Doesn't really sound like you want to figure it out

You haven't answered the mileage question yet.
Doesn't sound like you checked compression either.

I mean, you have to put some effort into it.

Also, you should have a Motorcraft PCV valve installed. As aftermarket valves are much too restrictive and they most definitely will use oil with one of those.

That can get bad enough to the point it will fill the lower intake with oil and cake the heads with sludge.

Something you don't want to let go for too long.

Good Luck!

 

Let me answer all of your questions. I may have been lazy typing but we have "put some effort" into it.

Truck has 200,000 miles but blew a head gasket so we replaced it with a used engine from a very reputable parts place. They checked the compression and oil pressure before selling it. We checked both after getting the engine running and I don't remember the numbers exactly but compression was something like 150 to 175 and didn't vary between cylinders by more than 5-10 pounds. Oil pressure was good too. Has the adapter for the oil filter instead of the remote unit but still no leaks.

We did replace the pcv and I don't know if it was a Motorcraft or not. If that can make that big of a difference I will check it or just replace with a Motorcraft unit. If the pcv is too restrictive where does the oil go?

2.5 gallons of oil in 700 miles it seems like it should smoke like a battleship or be leaking from every orifice. Engine runs great, smooth with lots of power.

 

Forgot to add, the used engine supposedly had less than 100,000 on it. Again, I can't remember the number exactly.

 

Well, I don't know how long the cats can survive with that much oil consumption, actually have never seen
a vehicle use a qt every 100 miles, but as you don't see the oil burners like we did years ago, that's because
of the cats, there will be no smoke.
One of our cars, an Optima Turbo, don't rub it in but it's a fun car to drive with the 285HP and only 3200#,
was using a qt/325 miles, no smoke at all, but Kia did replace the junk engine because of oil consumption.

 

Sucks it right through the breather, into the intake and through the TB... Some drops into the lower intake and collects, the rest through the engine. There will usually be evidence of this inside the TB and elbow...oil river running through the bottom, oil coating inside everywhere. If you combine the wrong PCV with a half plugged air filter or poor maintenance, and more less knockoff/inferior replacement parts... it can get serious.

PCV valve is a major player though. Modulars need one with wide margins.

A pic from user akdoggie , member of this site, -

 

We had to special order the PCV valve from Ford today. I'm thinking about running it with the vacuum hose blocked off and the pcv valve in place just to keep oil from splashing out. I don't think this will hurt anything except the check engine light may come on. Wrong or correct?

 

Wrong lol.

They're under 5 bucks here locally at 3rd party shops. Make sure you get the grommet with it, they usually come with. Should inquire all the same.

EV238

RA has them online. Amazon and Ebay might as well, -

https://www.rockauto.com/en/moreinfo...t=5052&jsn=936

Might want to feed a hose thru the TB down into your lower intake, If you can blow bubbles, prob be a good idea to extract the oil from it.