Burnin a lot of oil.....

[JPCY72]

Hey guys,

I just got this truck and who know ho many miles are on it. It has a 350 and it is burning about 1 quart every 150 miles. now I originally thought it was the valve seals but it doesnt smoke on startup. I dont know if it blows smoke when I take off. It runs great I did drive it up the grapvine and got 12.5 mpg! Freakin great. Im not in a postition to rebuild the motor yet, an old timer said that it could have a few stuck rings or is glazed over and he suggested to get the truck warm and drain the oil, then add 2 quarts motor oil two quarts atf and top it off with some diesel fuel. Then start the engine let it idle crack the throttle one time then let it sit for 15 minutes and repeat once then drain the crankcase. After 2k miles drain the oil if it is still dirty repeat. Now i have known this guy for a long time and he has bee building motors for 30+ years and all his stuff runs great and forever... My interpertation is this will wipe the walls of the cylinder and loosen up the rings. Atf is a detergent oil and diesel is thin but still and lubricant. What do you guys think..... ps not my daily driver.

[Longhorn Man]

are you 100% sure it's burning it all? I would think a quart every 150 miles would smoke like mad.
When was the last time the oil and filter was chainged?

[westofb]

Check your intake gasket. I had a fresh rebuilt 350 that after having no problems for about 1000 miles, it started using oil. It finally got to the point that it was using a quart every 100 miles, there were no visible leaks, and no smoke what so ever. After starting to tear it down to find problem (luckily it was still in the truck), when I pulled the intake gasket, could see where it was sucking oil from the lifter valley. Put in new intake gasket and no more oil consumption. I would not have believed it myself if it had not happened to me. I mean a quart every 100 miles....you would think it would be blowing huge plumes of gray smoke out the exhaust. I would pull the intake first to check, this is an easy fix if that is the problem.

[JPCY72]

Thanks the intake never crossed my mind and I have a GMPP ZZ4 Dual plane so that may get to go on sooner than I thought worth a check I guess....

[68gmsee]

I've never seen a vehicle that loses that much oil and not leave some sort of trail either of smoke, puddle on the driveway, or oil underneath the frame and/or behind the motor.

I would have someone follow you as you drive it and gun it a few times to see if puffs of smoke come out. You got to have some sort of evidence.

[1970 Bowtie]

You say it is burning oil but your truck does not smoke.Sounds more like you are losing a quart of oil every 150 miles.Have you pulled the radiator cap to see if the coolant looks a choclate milkshake?I have an older ford(yes I said Ford)that would use oil with no smoke or leaks,but my coolant was like a milk shake.Turns out it was a head gasket. Fixed it ,no more oil loss.

[rambler]

I agree with everyone there, if its the rings, you would be blowing blue smoke, I had a old rambler like that, had another chevy was leaking out the rear main seal.

and another was the headgasket, but that overheated as well... check what the dipstick says. also never hurts to change the oil.. see what comes out...

let us know what you find out.

[69halfton]

70 bowtie beat me to it, i was going to say check your coolant.

i would have to agree, if your using that much it would smoke when you floored or something.

do you park on a gravel driveway and not always in the same spot? could be a leak if thats the case.

[Longhorn Man]

it would smoke any time it is running, and for 15 min after shut off.

[JPCY72]

ok so I looked at the truck there is no oil patch on the ground I know cause it parks in the same spot all the time and my driveway is dirt also when the alternator went out it was parked in my uncles clean driveway and no oil slick there either. There is however black stuff in the exhaust there isnt blowby on the axle or the frame or the bumper Id expect there to be oil mist on the tail gate because the exhaust exits under the truck straight back.
i didnt have anyone watch me drive so that will be the one last test. I purchased some intake gaskets for my new manifold Im sure that will help if anything. I will keep you up tp date. thanks guys. -Steve

[williamt]

have you switched to non baffled valve covers? can't malfuntioning pcv valve suck oil into the carb?

[Longhorn Man]

when was the oil chainged last?

If the oil is very old, or if the carb is real rich, the fuel will dilute the oil. If it leaks/burns a little, the fuel can fill it at a similar rate. This is even worse if it is only used on real short trips.
Then when you drive it and get it up to operating temp... the fuel burns away from the oil leaving the oil level low.