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Too much Oil

My dad says putting too much oil into my car will hurt it. I don’t think so.

Is there harm in over-filling an engine with oil?

If the oil level in the crankcase gets high enough where it is close or comes in contact with the rotating crankshaft, the crankshaft can entrain air into the oil. If enough air gets entrained into the oil, the oil pump cavitates with this air, and the engine loses oil pressure.


Exactly, fill it to the maximum level but not above.

Tester is correct. In other words, the crankshaft can whip air into the oil and then no oil will enter the engine since it will be full of bubbles and froth.

thanks! I think this is what has happened. Will an oil change fix it?
Isaac’s Dad
Symptoms are a drop in oil pressure. Also, he mentioned it was not shifting into second properly - but I am wondering if that is a related symptom.

What has happened to the engine? is it losing oil pressure while running or has it had more serious symptoms?

“Will an oil change fix it?”

Only if you are lucky.  Don't try to start the engine until you have drained it back to normal.  With luck no damage has been done.  If you can provide a detailed description of what has happened, we should be able to give you a much better idea.  It could be nothing to very serious and expensive.

You over filled the oil? How much over? If it’s a quart, or less, don’t worry about it.
If it’s over a quart, you can drain some out; or, if you have a hand pump with a tube, you can hand pump the excess out.