Rumors since I was a teenager suggest that overfilling an engine with oil may somehow damage it. The vehicle in this case is a 1986 Camaro Z28 with Mobile 1 oil so light in color it is hard to read on the dipstick. What is the real story here? I suspect that it may have something to do with the engine throwing out oil in quantity leaving too little for safe operation. Since I have an analog oil pressure gauge, that would be apparent immediately. Thanks for all responses!
Engine Oil Overfill
Aug 06, 2003
4 Replies
This wouldn't apply to a dry sump type system... as the oil is all scavenged from the oil pan out into a separate storage.
In other engines, the crankshaft is setting right above the oil laying in the oil pan. With too much oil, the crank acts just like an egg beater and whips the oil into a froth. Now you don't have oil any more, you have oil froth which does a lousy job of lubricating.
I don't know how high it would take to froth it. One time I drained
7.5 qts. from a 2.8L Aerostar that had not foamed up. (The quicky oil change place gets credit for the fill.)I'll bet the Slant Six ran forever afterwards.
1000 years ago, when I worked in a gas station/towing operation, we used to try different ways of blowing up engines on wrecks that got towed in. Buy the VHS video, features such old favorites as:Brick on the gas pedal. Above plus slit lower hose and drain out coolant first. Above plus drain out engine oil. Above plus then add water to crankcase.
We had a Duster that took two weekends to blow up. One Ford Granada, with a straight Six, took an hour to blow AFTER it had a softball-sized hole in the block. You could hear that engine screaming in pain a block away.
Damn, what fun.
Hey, d> > > If you get enough of an overfill, it could cause the crankshaft to start
The problem is foaming. When you over-fill, the crankshaft will whip the oil in the pan to a froth so that what is getting pumped through the engine is oil with entrained air, not just oil.
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