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Too much oil can cause engine damage in your car

Based on long experience, I always check the oil level immediately after an oil change. Recently on a GM dealer oil change I discovered they had overfilled by almost a litre. They said it was nothing to worry about but, at my request, took out the excess oil – telling me about the problem they had been having with metering oil into cars from their big tank of bulk oil. I phoned GM and they told me that overfilling by that amount was indeed a problem and that it could result in engine damage. If auto design experts drop the dipstick, they had better have warning of overfilling – especially when their dealers have faulty metering systems in their oil filling procedures. – Richard

Yes, too much oil could have been a problem, maybe not at that degree of overfill, but there is a possibility of damage when the level in the oil pan is too high.

The result is that the spinning crankshaft can aerate the oil, whip it into a froth or foam as it moves through with each revolution. That oil, with tiny air particles in it, cannot do a proper lubricating job. In severe cases, insufficient oil flow could result in overheating – not a good thing.

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Dipsticks are only good if they are used. I suggest that anyone who overfills and admits it happens on occasion due to faulty equipment, does not check his or her work and a dipstick is of no use.

Send your auto maintenance and repair questions to globedrive@globeandmail.com

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