What are the indications of oil pump shaft shear?

What are the indications of oil pump shaft shear?

• A. Oil and RPM reading 0, high EGT
• B. Oil pressure rising rapidly
• C. Normal operation
• D. Low oil temperature

Answer: (A)

Oil pump shaft shear stops the pump from circulating lubrication. When that happens, oil pressure collapses to zero. Without oil, bearings and gears overheat quickly, which can cause the engine to lose rotation or shut down, so RPM can drop to zero. The lack of lubrication also drives heat up, showing as a high exhaust gas temperature. So the telltale signs are zero oil pressure, zero RPM if the engine shuts down, and high EGT. The other options don’t fit: a rapid rise in oil pressure wouldn’t occur with a pump failure, normal operation isn’t possible, and low oil temperature would not be expected when there’s no oil circulation to cool the engine.

Oil pump shaft shear stops the pump from circulating lubrication. When that happens, oil pressure collapses to zero. Without oil, bearings and gears overheat quickly, which can cause the engine to lose rotation or shut down, so RPM can drop to zero. The lack of lubrication also drives heat up, showing as a high exhaust gas temperature. So the telltale signs are zero oil pressure, zero RPM if the engine shuts down, and high EGT. The other options don’t fit: a rapid rise in oil pressure wouldn’t occur with a pump failure, normal operation isn’t possible, and low oil temperature would not be expected when there’s no oil circulation to cool the engine.