>> C << Thermostat Housing Installation

WARNING: This page is about a different car, the 2003 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.

Apply a 3 mm (0.1 inch) diameter bead of sealant MITSUBISHI Genuine Part number MD970389 or equivalent to the groove as shown in the illustration.

Fig 1: Identifying Sealant Application Surface Of Thermostat Housing
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Install the housing quickly (within 15 minutes) while the sealant is wet and tighten the bolts to the specified torque.
1. Tightening torque: 23 +/- 4 N.m (17 +/- 3 ft-lb)
  NOTE: After installation, keep the sealed area away from the coolant for approximately one hour.