Burning or loosing oil?

[tino0217]

I have a 71 C10 350 small block I recently did some timing on the truck that I was having issues with when I got as close as possible to where it was running with no backfiring but some bogging at top speeds before having to shift on the road I went for a drive for about 30 miles realized I was burning oil or something because I had to add to quarts of oil just after an oil change got back from my destination had to add two more quarts. So now I emptied the oil pan I had two quarts of oil in my truck the water was low but I have to remind you that when I was driving there was no smoking and engine was idling fine but was sputtering a little bit I had to add about three quarters of a gallon of prestone I shot it down with purple magic degreaser and I will look for a leak tomorrow but any ideas what might be causing this? After draining the oil there was no signs of water, I also checked a couple of the spark plugs and they looked fine.

[MAC71Cheyenne]

Dang...valve seals? Rings? Oil pan gasket?
I think I would pull all the plugs and see what they look like. Could be a head gasket starting to fail.
Chime in here fellas before we loose an engine....

[HO455]

I have had new oil filters that leaked. You might want to start looking there.

[Sheepdip]

Otis uses about a quart to every 4-5 tanks of fuel depending on work load.
What I have not figured out yet is right after a fresh oil/filter change Otis sucks a quart down in roughly 2 tanks of fuel then settles back into to the 4-5 tanks of fuel oil consumption.

No leaks all internal consumption.

[RustyPile]

Originally Posted by Sheepdip

Otis uses about a quart to every 4-5 tanks of fuel depending on work load.
What I have not figured out yet is right after a fresh oil/filter change Otis sucks a quart down in roughly 2 tanks of fuel then settles back into to the 4-5 tanks of fuel oil consumption.

No leaks all internal consumption.

How many miles is 4-5 tanks??? Consuming a quart of oil every 800 - 1,000 miles in an old engine with lots of miles on the odometer isn't what I'd call excessive.. The oil loss immediately after an oil change could be because sludge build up has blocked the oil drain back holes in the heads and oil is accumulating "up top"..

[geezer#99]

The old saying was ‘one drop of oil every 100 feet makes one quart in a thousand miles’.

Could be you’re overfilling the crankcase sheep dip. Crank picks up the oil and it gets burned getting past the rings.

[Sheepdip]

Originally Posted by RustyPile

How many miles is 4-5 tanks??? Consuming a quart of oil every 800 - 1,000 miles in an old engine with lots of miles on the odometer isn't what I'd call excessive.. The oil loss immediately after an oil change could be because sludge build up has blocked the oil drain back holes in the heads and oil is accumulating "up top"..

Well I didn't intend to hi-jack this guy's thread I was just giving him/her a comparison on my usage....I'm fine with the oil consumption on this 50 year old truck, no leaks when he sits so something is getting oiled as it goes out the exhaust pipes is the way I look at it.

[REDROCKER652002]

I had a 79 Z28 that kinda had the same issue I was losing oil and not seeing anything coming out of the tailpipe. Turned out, the valve guides on the number 8 cylinder were bad,causing the oil to blow by and foul the plug. I also had an issue with the head gasket on that side too, but the valve guides were the main issue. And this was a newly rebuild set of heads I paid a pretty good amount to have done by a "race engine" guy. I'd pull the plugs and see what you got there.

[gmc684x4]

Check the oil filter is a good idea
Some times old seal sticks to block and doubles up on new filter not making a good seal

[uncle]

I had a problem similar and was intake gaskets.

[pjmoreland]

Originally Posted by uncle

I had a problem similar and was intake gaskets.

I did too. My engine started consuming about a quart every 100 miles because my intake manifold bolts were loose. It developed a rough idle and the plugs got fouled up. Replacing the intake manifold gaskets and retorqueing the bolts after driving a few times solved the oil consumption.

['68OrangeSunshine]

I was running a 292 that had about 200,000 on it, so I was not surprised it was burning oil.
What was strange, was that oil consumption wasn't too bad if I was mainly driving tound town, but it lost a quart for every hour on the freeway at high speed.
Mystery was solved when I tore it down after 250,000. The Harmonic Balancer had gone off its rubber mountings and was rubbing on the timing gear cover. This wore a gash in the sheet tin, and at high RPMs the oil gushed out. The 292 is the bigger industrial L6, It had a 3-groove pulley that was part of the Harmonic Balancer.

[heritage03]

I would say its the valve stem seals IMO. I have a 454HO crate engine in my 69 Camaro and had the same issue. Used quart every 300 to 400 miles and that was using 20-50. Changed to positive seals and no more oil use.

[MAC71Cheyenne]

Just for fun, had a '78 GMC with a 400 in it. (bought new) with about 15k miles on it I was going through the oil like a Louisiana thunder storm. No smoke, exhaust pipe wasn't oily. Replaced the valve seals and good as gold until I sold it, regretfully now.

[tommy3horse]

Possibly intake gasket slipped, mine did and new GM crate 350 went thru oil at a pace of 1qt per 100mi. Pulled the intake and found the gasket slipped down by #6 cylinder and it sucked oil and fouled the heck outta the plug. New Fel-pro gaskets and proper torque, fixed. Plugs can be a great insight into your motor.
Good luck!

[pjmoreland]

Here are two photos of the same spark plug before and after replacing my intake manifold gaskets.

[tino0217]

Turns out it was my valve cover gasket on the driver side. I screwed up an put permatex on both sides of the gasket. I've replaced the gasket with a just a slight layer of permatex on the one side now I just need to recharge my battery today and see if it's all good