Will 5 quarts hurt a 1991 Honda Accord engine?

Answer 1

My question to you is why would you add 5 quarts of oil to an engine that the manufactures recommends you only add 4.5 quarts with oil/filter change. That is a waste of 1/2 quart of oil and is very unwise. But, to answer your question, it may do no harm and then again it may very well be harmful. Anytime you overfill any engine you risk internal engine damage as the excess oil can make contact with the crankshaft and cause cavitation which will result in air being mixed with the oil. This air/oil mix is a poor lubricant and the result will be engine wear. My advice is to remove the excess oil immediately. Just drain out 1/2 quart or drain it all out into a clean container and then pour it all back in minus that 1/2 quart. That way you know you are 100% safe.