Im looking into buying a 1993 Ford F-150 extended cab short box with 59,562 miles on it, it was babied most of its life, but in the last year, it loses about a quart of oil to every tank of gas through it, the compression is awesome, there is not one drop making it to the ground, and has had heads off and none leaking to be burnt off, no smoke no nothing, what could it be.............?

 

What were the compression figures?

 

If there is no visable sign of leaks then it has to be burning it. It might have been babied but has it been taken care of ie: oil changes ,tune ups ,eTc.

 

I went and looked at it, they have all of the maintence records through ford and the only thing they have done to it is new plugs, wires, cap, rotor, and fuel filter. The compression checked out at 7.5 to 1..... i dont know if this is good or bad but the guy said it is good...

All of the oil changes are on the local Ford dealerships computer so its been maintained

 

Check the PCV valve. If stuck, they can cause oil burning. You are right at the required 60,000 mile replacement interval.

A compression check will not test for bad valve guide seals, another source of oil consumption. Age, not miles may be a factor with seals. You might want to try a "high mileage" oil to see if that helps.

Jim

 

I thought you meant compression test was good, 7.5:1 means nothing as to weather or not a motor is in good condition that fellow is pulling your leg on that one, that just means the motor has stock compression ratio but 7.5:1 still seems low to me. Go get a compression tester gauge they run $15 +/- and if the motor has a starter on it take all the plugs out unhook the coil and test each cylinder for pressure. Follow the directions with the gauge IF one is way off then there is where the oil is going, it should show a low number if there is a problem with the seals as well you just won't be able to know weather it is rings or seals unless you do a leak down and or know how to read the gauge as in how it builds up pressure with each revolution of the engine. IF possible see if they will let you have a leakdown test done on the motor as this would pinpoint exactly what is wrong or at least rule out anything mechanical/seal . It may very well be the PCV valve which is a $2 part but I would test the crap outta that motor before you buy it especially if your looking for a drop in motor with no initial extra work being done to it. Could be worn seals as previously mentioned but my point is make sure know why it is burning oil before you buy, don't assume or it may catch up with you in the future. Hope this helps some