Replacing VW Thermostat Housing – Volkswagen Repair Denver
Volkswagen and Audi starting using plastic thermostat housings on most of their V6 cars around model year 2000. Earlier model years used an aluminum housing. We have not seen a lot of the later plastic housings leak if they are not disturbed. We have seen them leak after a thermostat has been replaced. Replacing a thermostat on one of these vehicles is common practice when a timing belt is done, because it is not uncommon for thermostats to malfunction and replacing one involves removing the timing belt first.
If you replace the thermostat it is a good idea to also replace the thermostat housing. A new plastic housing is a reasonable replacement and should last the life of the thermostat. For high performance, turbo applications or customers just looking for a little peace of mind backdating to the more durable aluminum housing for about $70 more is a good choice.