If the oil pump regulating valve sticks open, which of the following is NOT a likely symptom?

• A. Decreased oil pressure.
• B. Increased oil consumption.
• C. Decreased oil consumption.
• D. Increased oil pressure.

Answer: (D)

The oil pump regulating valve controls engine oil pressure by bypassing excess oil back to the sump to keep pressure within spec. If this valve sticks open, more oil is diverted away from the bearings, so the system can’t build normal pressure. The direct and likely result is decreased oil pressure. An increase in oil pressure would not occur in this fault (that would happen if the valve stuck closed or blocked the bypass). So the symptom that does not fit is increased oil pressure.