Do not remove the pressure cap from a hot engine. Wait until the coolant temperature is below 50°C [120°F] before removing the pressure cap. Heated coolant spray or steam can cause personal injury.
NOTE: The N14 CELECT™ and CELECT™ Plus engines have one engine coolant thermostat and one aftercooler thermostat. The N14 STC engines have two engine thermostats and no aftercooler thermostat. The illustration reflects the N14 CELECT™ engine, but is representative of all the engines.
The engine thermostat and the thermostat seal must operate correctly for the engine to operate in the most efficient temperature range. Overheating or overcooling will shorten engine life.
Remove the upper radiator hose from the thermostat housing.
Suspend the thermostat and a 100°C [212°F] thermometer into a container of water. Do not allow the thermostat or the thermometer to touch the sides of the container.
Heat the water.
Record the temperatures at which the thermostat begins to open and when it is fully open.
Hello, I'm Jack, a diesel engine fan and a blogger. I write about how to fix and improve diesel engines, from cars to trucks to generators. I also review the newest models and innovations in the diesel market. If you are interested in learning more about diesel engines, check out my blog and leave your feedback.
View all posts by Jack