W 250 Pickup L6-359 5.9L DSL (1989)
Thermostat: Testing and Inspection
Check the thermostat operation by placing it in a flask of heated water. The thermostat operate as follows:
1. Maximum start to open at 83°C [181°F].
2. Maximum fully open at 95°C [203°F].
Replace the thermostat if its operation is other than above.
