My 2008 Mini Cooper-S burns more oil than I would like (1 qt/3000 miles) but I am told “They all do that.”. When I topped up recently, I think I overfilled it and oil level on the dipstick (which is very hard to read on these cars) is well above the max The manual cautions to not overfill with oil. What are the dangers of overfilling the engine with oil?
If it is only a 1/4 quart you should be OK since it burns it off. Over filling to the point where it hits the crankshaft will cause the fluid to aerate and fluid full bubbles can not be pumped where it is needed.
If the oil begins to foam after overfilling…it will affect the oil pressure. That affect is lower pressure and the possibility of the bearings not being properly lubed. I would get a second opinion on your overfilling and get that excess oil out of the crankcase. A good independent mechanic can take care of that for you.
Is it over filled the width of 1 finger? 2 fingers? Your hand? If the engine is running while severely overfilled oil will be pushed up and out the dipstick tube.