Audi began using a Nylon 66 glass filled (plastic) thermostat housings in 2001. These are now up to 14 yrs old. Owners are discovering the problems when these warp and crack. Some of the plastic housings leak right after replacing the thermostat due to warping. Labor cost to replace can be over $200. The solution is to replace with the more expensive but reliable pre-2001 aluminum factory part shown here during the timing belt service.
This one is in excellent condition for a used part. This is the actual part you will receive.
This is the critical o-ring sealing surface.
When selecting a good used housing, this must be in excellent condition or you risk another leak.
Comes with a new thermostat O-ring. Compare this to new at $130+ for aftermarket. This is an OEM part.
078-121-121J
078 121 121 J
078121121J
$80 shipped in the lower 48 states
Located in Kansas City
Contact Chris here - --e-mail LINK--
Link to repair article
Link to forum post on housing part numbers
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