Oil oxidation, as a result of excessively high lube oil temperature, is harmful to a diesel engine because __________.

Correct Answer: Option C — corrosive by-products are usually formed

Excessively high crankcase temperatures accelerate lube oil oxidation, breaking down hydrocarbon chains and generating harmful organic acids, varnish, and sludge. These corrosive by-products attack bearing metals and internal engine components, necessitating strict temperature monitoring per marine diesel operating standards.