Practice question

A school bus diesel oil filter shows a partially open bypass and the oil is heavily contaminated. Continued operation in this condition will MOST likely cause:

  1. Improved engine longevity
  2. Accelerated bearing and component wear because unfiltered oil is circulating
  3. Lower coolant temperature
  4. Higher fuel octane

Answer: B — Accelerated bearing and component wear because unfiltered oil is circulating

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