Oil temperature and pressure during start: what are the minimum oil temperature, maximum pressure without damage, and action for exceedance?

Oil temperature and pressure during start: what are the minimum oil temperature, maximum pressure without damage, and action for exceedance?

• A. Oil temperature above 0 °C; oil pressure up to 128 psi; exceedance referred to maintenance.
• B. Oil temperature above -10 °C; oil pressure up to 120 psi; exceedance referred to maintenance.
• C. Oil temperature above 10 °C; oil pressure up to 150 psi; exceedance referred to maintenance.
• D. Oil temperature above 0 °C; oil pressure up to 128 psi; exceedance ignored.

Answer: (A)

Oil lubrication during start must be within safe limits to protect bearings and the oil system as the engine spools up. The minimum oil temperature of 0 °C ensures the oil isn’t so viscous that it won’t flow properly, which could starve lubrication during initial rotation. The maximum oil pressure of 128 psi keeps the system within its design limits; higher pressures can indicate a fault (such as a blocked passage, stuck relief valve, or sensor/gauge issue) and could damage seals or clearances. If oil pressure exceeds 128 psi, the procedure is to refer the issue to maintenance for investigation before continuing operation. This emphasizes diagnosing and correcting potential oil-system faults rather than proceeding with a risky start. Other options either set an inappropriate temperature (too low or too high for safe cold-start lubrication) or an incorrect pressure limit, or they treat an over-limit pressure as something to ignore, which is unsafe.

Oil lubrication during start must be within safe limits to protect bearings and the oil system as the engine spools up. The minimum oil temperature of 0 °C ensures the oil isn’t so viscous that it won’t flow properly, which could starve lubrication during initial rotation. The maximum oil pressure of 128 psi keeps the system within its design limits; higher pressures can indicate a fault (such as a blocked passage, stuck relief valve, or sensor/gauge issue) and could damage seals or clearances.

If oil pressure exceeds 128 psi, the procedure is to refer the issue to maintenance for investigation before continuing operation. This emphasizes diagnosing and correcting potential oil-system faults rather than proceeding with a risky start.

Other options either set an inappropriate temperature (too low or too high for safe cold-start lubrication) or an incorrect pressure limit, or they treat an over-limit pressure as something to ignore, which is unsafe.