I have a problem with bad oil consumption, my truck uses 1 quart of oil in 300 miles, with no signs of smoking. I recently purchased an 82 F-250 4X4 with a 400M in it, it had 86,000 original miles on it. ( papers to prove it )The truck was only driven short distances all its life, he lived only about 8 -10 miles from work, then used it to pull wagons on his hog farm. This caught way off gaurd as the truck runs great, I've checked it out completely, compression check showed 150-160 lbs per cylinder, checked valve guides with vacuum gauge, 18 lbs with a steady needle. So I replaced the valve stem seals as I had some smoke on cold start up & decceleration. The valve stem seals cured this but it still is using oil like crazy. NO engine oil leaks that amount to anything. I can park it my garage for days it may leave a spot the size of a quarter, no leaks while running , the truck is dry underneath. PCV system is working properly. I'm lost!! No fouled spark plugs either. Help!!!

 

Maybe some of that oil dye will help find the leak- if there is one.

Just to be safe, although improbable, check the tranny and radiator for oil. It's got to be going somewhere.

Neal

 

Super, So if its not leaking then it has to be burning. Has any of the oil gotten into any of the hoses(radiator, heater?) When I haven't driven my truck for awile, when I give it a hard highway run, the dipstick shows that I need to add oil, I wait and maybe drive it around town for a bit, and the dipstick shows full the next day...Any tailpipe smoke?

 

Pastmaster, yes it has to be burning it somehow, And as dumb as this sounds NO it does not smoke, as I mentioned it had smoked on cold start-up and deceleration, replaced the vavle stem seals, now it dosen't even do that. No I don't have any oil in the coolant either. There is no smoke on full throttle acceleration and then doing the same and then letting off of it quickly. No smoke at cruise speed, but I'm sure its burning it somewhere. I don't know if I have an internal vacuum leak on the intake where it may be drawing oil from the lifter valley, stuck oil rings or ring, or the vacuum test isn't reliable to check the condition of valve guides. I've put some Rislone in it to see what happens, then I'll go from there. I'm still open to suggestions. . This one is going to be a bear to figure out!!

 

Have someone check the PVC system. If it gets plugged up it can build up pressure in the crankcase and force oil out even into the air filter or other areas. It might be as simple as replacing the PVC and its filter.

 

insect2, I've thoroughly checked the PCV valve system to make sure its working properly, and it is.

 

Seems that if it were burning that much oil, there'd have to be some smoke. Is your exhaust black and sooty? Can you SMELL anything?

Neal

 

nomo, yes my tailpipe is pretty black and sooty. The exhaust does smell a little funky. Its not the catalytic converter as this truck is a heavy emmission truck, (I guess you could say its a 1 ton 3/4 ton), and has no converter, its stated so on the core support and valve cover decals NON CATALYST ENGINE. No " unleaded fuel only " on the gas gauge or fuel tank doors either.

 

Get a white sheet of paper - or some light colored anything - and hold it in front of the exhaust pipes while someone "revs up" the engine. Maybe it's blowing the oil out instead of burning it????