ISM, ISMe, and QSM11 – 007-039   Lubricating Oil Thermostat

• Remove the lubricating oil filter head. Refer to Procedure 007-015 in Section 7.

Use snap ring pliers to remove the snap ring in the thermostat bore.

Remove the lubricating oil thermostat.

WARNING  The flash point of new lubricating oil is approximately 221°C [430°F]. Do not allow the oil temperature in the container to exceed 149°C [300°F]. Do not allow water droplets to enter the container of hot oil. Water droplets will cause a violent reaction, which can cause personal injury.

Suspend the thermostat and a 116°C [240°F] thermometer in a container of new lubricating oil. Do not allow the thermostat or the thermometer to touch the sides of the container.

Heat the lubricating oil.

Write down the temperature at which the valve is fully extended. The valve must be fully extended to at least 6 mm [0.250 in] from the closed position when the temperature reaches 116°C [240°F].

Replace the thermostat if it does not operate as described.

Insert the oil thermostat into the filter head. The beveled end of the thermostat goes in first.

Install the snap ring into the groove using snap ring pliers.

CAUTION  Engine oil pressure must be indicated on the gauge within 15 seconds after starting. If oil pressure is not registered within 15 seconds, shut off the engine immediately to avoid engine damage. Confirm the correct oil level in the oil pan.

• Install the filter head onto the engine. Refer to Procedure 007-015 in Section 7.
• Operate the engine at idle speed for three minutes to inspect for leaks at the filter head.