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Oil Consumption 331 Engine

Started by STEVE CLC #16187, February 12, 2012, 06:42:15 PM

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STEVE CLC #16187

My neighbor has a 1950 Cadillac 331 that lately has been using a lot of oil, 2.5 quarts the other day after about on 500-700 miles, This is the second or third time it has  got that low. The strange thing is it does not smoke, there is no blow by coming out of the road draft tube, and I he has not pulled the plugs but the car does not seem to miss at all and runs strong. My questions is where is the oil going ? compression is good . Any Ideas ? I remember  the valve guides would wear on some GM Engines and you had put the umbrellas on the intake valves  or the oil would foul your plugs . Could this be the case with the 331 engines?

steve
steve hales
clc # 16187

Eldovert

I wonder if he is pulling it through the vacuum pump in the engine ?
Cheers,Pat MacPhail

R Sotardi #11719

I have an original 1950 with the 331. Heads have never be off with 86K miles. I'm the second owner. I get about 600 miles to a quart. How many miles on his(her) engine. Are the plugs clean? What Grade of oil is he using? As the engines wear, the rings lose their sealing ability and the cylinders get a bit of an hourglass effect. This is normal wear. What is the compression? Is it within  @ 10PSI each? Mine is about 100-110 PSI.Any leaks in valve covers? Does it smoke on startup? That would denote valve stem seals are not preventing the oil from dripping down into the combustion chamber. I would not worry too much if the car does not smoke, or run rough. Try a slightly heaver oil, say a 10w40 or 20w50. Do a good test for mileage usage. Ron

Roger Zimmermann

The oil is probably on the road! The rear seal at the crankshaft is notorious for loosing oil. How to notice it? Well, the undercarriage must be very greasy...
The cure: install a rubber seal from Best Gasket. I did that on my '56 de Ville and '57 Brougham. Their frame is now dry...
1956 Sedan de Ville (sold)
1956 Eldorado Biarritz
1957 Eldorado Brougham (sold)
1972 Coupe de Ville
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