MTU Detroit Diesel 183 Series Technical Publication page 557

Task Description
20080/1 E 98-12
Continue to heat coolant to full-opening temperature.
Full-opening temperature = 94 °C
Thermostat insert must be completely open after
approx. 6 to 8 minutes.
Measure coolant thermostat stroke travel.
Stroke must be 8.0 mm; if not, replace thermostat
insert.
Installation
Check sealing and mating faces.
Grease new O-rings with petroleum jelly and insert in
coolant distributor housing.
Insert thermostat elements, with ventilation notches
facing upwards, into coolant distributor housing.
Install thermostat housing with hex screws.
Group 20
Subgroup 2470b
Page 3