Please what is the effect of an overgauged engine oil on the engine performance? I bought a litter engine oil from a filling station to top up the oil level on my car and just discovered the new oil level is above the gauge mark. I hope it isn't as bad as when the engine oil is undergauged, or short?
Auto engineers, pls comment.

Plenty.

It will kill the main bearing oil seal, among other things.

Simply, unplug the oil drain plug and drain out some quantity and re-tight the plug. Yes, its likely to go below normal gauge when you do that. But thats the price you have to pay. You can always buy new can of oil of the same oil grade in the engine, and gradually refill to normal level on the dipstick.

Ikenna

Ikenna. Thanks. I will drain the oil a little to the required level.