oil consumption
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Elder User
Joined: Dec 2002
Posts: 608
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From: TAOS NM
oil consumption
hey, my 69 351w is using up lots of oil, funny cause she don't leak at all.
can someone please tell me what this means ,and what will it take to correct this? , also when i start her up in the morning she sprays out black water from the tail pipe, you can tell where i park cause of the black spay marks. please help my torino?
thanks.
can someone please tell me what this means ,and what will it take to correct this? , also when i start her up in the morning she sprays out black water from the tail pipe, you can tell where i park cause of the black spay marks. please help my torino?
thanks.
Last edited by forddytube; Apr 18, 2004 at 09:59 PM. Reason: spellin erros
Senior User
Joined: Jul 2003
Posts: 204
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From: Montana
If it's not leaking oil, must be burning the oil. Oil will be drawn down the valve guides past the old tired valve stem seals, and past the tired piston rings into the combustion chamber where the oil is burned in the combustion cycle. Water is a major by product of gasoline engines, and mixed with burned oil should make the black marks your talking about.
See if when you first start the car in the morning, is there a blue cloud, if so this is valve guide oil consumption. If there is a blue cloud when accelerating away from a stop, then this is piston ring oil consumption. You may have both.
Take a look at your spark plugs, they should have heavy carbon deposits from burning oil. The cylinder head valve heads will have large deposits of caked on oil on the side of the intake valves facing away from the combustion chamber. Eventually the deposits will thicken enough to hold the valve open slightly, causing the face of the valve to burn, then the engine will start missing on that cylinder. A valve job is typically recommended to fix the oil consumption problem. But if you do this on a tired engine, the extra sealing of the valve job will put more pressure on the old piston rings, causing even more oil burning past the rings. So a complete engine rebuild is the ultimate answer.
A backyard cheap way out would be to remove the heads, rent a valve spring compressor, take the heads apart (remove spring retainer, keepers, valve, and valve guide seals. Then use a wire wheel on a bench grinder to clean up the valves. Use wire wheel on electric drill to clean up the cylinder head combustion chamber and valve seats. Then use valve lapping compound to lap in the old valves to the old seats. Reassemble the valves, springs, etc with new valve stem seals. Will need new cylinder head and intake manifold gaskets. This will fix the valve stem oil leaks, though the piston ring oil consumption can be the big oil burner. I''m sure I'll get scolded by forum members for suggesting such a cheap way of fixing the problem, but I've worked at small car repair shops where not every customer had lots of cash to spend, and what I've just suggested can help the engine run another 30,000 miles.
Keep in mind your tired engine could probably use a new timing chain if its as tired as it sounds.
I saw a guy take his chevy v8 apart, hand stretch the piston rings, lap the valves by hand, and 2 years later it was running good as ever. Read "The Grapes of Wrath", they seated valves with a large hammer and a heavy blow which is what was called out in the Ford Model A service bulletins of the day.
See if when you first start the car in the morning, is there a blue cloud, if so this is valve guide oil consumption. If there is a blue cloud when accelerating away from a stop, then this is piston ring oil consumption. You may have both.
Take a look at your spark plugs, they should have heavy carbon deposits from burning oil. The cylinder head valve heads will have large deposits of caked on oil on the side of the intake valves facing away from the combustion chamber. Eventually the deposits will thicken enough to hold the valve open slightly, causing the face of the valve to burn, then the engine will start missing on that cylinder. A valve job is typically recommended to fix the oil consumption problem. But if you do this on a tired engine, the extra sealing of the valve job will put more pressure on the old piston rings, causing even more oil burning past the rings. So a complete engine rebuild is the ultimate answer.
A backyard cheap way out would be to remove the heads, rent a valve spring compressor, take the heads apart (remove spring retainer, keepers, valve, and valve guide seals. Then use a wire wheel on a bench grinder to clean up the valves. Use wire wheel on electric drill to clean up the cylinder head combustion chamber and valve seats. Then use valve lapping compound to lap in the old valves to the old seats. Reassemble the valves, springs, etc with new valve stem seals. Will need new cylinder head and intake manifold gaskets. This will fix the valve stem oil leaks, though the piston ring oil consumption can be the big oil burner. I''m sure I'll get scolded by forum members for suggesting such a cheap way of fixing the problem, but I've worked at small car repair shops where not every customer had lots of cash to spend, and what I've just suggested can help the engine run another 30,000 miles.
Keep in mind your tired engine could probably use a new timing chain if its as tired as it sounds.
I saw a guy take his chevy v8 apart, hand stretch the piston rings, lap the valves by hand, and 2 years later it was running good as ever. Read "The Grapes of Wrath", they seated valves with a large hammer and a heavy blow which is what was called out in the Ford Model A service bulletins of the day.
