Thermostat: Testing and Inspection

MAP Controlled Thermostat, Checking

Special tools, testers and auxiliary items required

• Connector test set (V.A.G 1594C)

- Remove Map Controlled Engine Cooling Thermostat ( F265). Refer to => [ MAP Controlled Thermostat ] Service and Repair.

• How to drain coolant. Refer to => [ Cooling System, Draining and Filling ] Procedures.

• Always replace gaskets and seals.

• How to fill coolant. Refer to => [ Cooling System, Draining and Filling ] Procedures.

- Check thermostat when cold: Large valve plat must seal all around against connection flange.





If this is not the case:

- Replace Map Controlled Engine Cooling Thermostat (F265).

- Connect contacts on Map Controlled Engine Cooling Thermostat (F265) to battery with adapter leads from Connector Set (V.A.G 1594C). Carefully insert it perpendicular to flange in a pot with hot coolant (mixture ratio: 50% G12+) using pliers.





CAUTION!
Metal parts of thermostat must not be touched because they get hot. Risk of burning!

The heating element also warms the wax in thermostat.

- Observe whether minimum range of 7 mm - arrows - is reached after 10 minutes.





If range of 7 mm is reached:

- Disconnect voltage supply to battery.

• This test should not be performed in air. Damage to the expanding material element cannot be prevented!

If minimum range is not achieved:

- Replace Map Controlled Engine Cooling Thermostat (F265).