MWM Acteon, Workshop Manual

Page: 160 / 215

13 - 4
Cooling System
9.612.0.006.7160 - 05/04
Thermostat Test Procedure
Test the thermostat and check its operation conditions
according to the procedure below:
• Place the thermostat in a recipient and fill with
water up the valve stays totally immerse.
• Position a dial indicator gauge on the stem of the
thermostat and adjust a pre-load of 1 mm.
• Install a thermometer of scale 0-100 °C immerse
into the water.
• Gradually heat the water up.
• Take note of the temperatures at the beginning
and final of the thermostat opening course
(beginning and end of the dial indicator gauge
movement), and the final total course of the dial
indicator gauge (fully open).
• Compare the values found with the table. Change
the thermostat if the temperature of the beginning
of opening is out of the specified values and / or
the total operation course is below specified.
Check the inspection hole located on the left side of
the engine block (seen by the flywheel side). If there
are signs of water or oil leakage, probably there is
leakage through the water pump or through the sealing
rings. Check and change, if necessary.