Hi gents, in the recent cold snap the heater would not really warm up for a couple of hours even after driving for most of that time, finally ran it down to a lazy thermostat which was just staying open more than desired so consequently it only got what I would class as really warm about an hour before I booked off for the day, a good quality replacement stat core is about £60 but Audi only sell it as the whole pipe with a new core about £90 so I went for that considering my existing unit had done 180k so therefore I could expect at least that again, now begins the horror of replacement you have to take the inlet manifold off to get at it so I opted for the cheat and unbolted the old thermostat housing its only three torx screws and an extension bar all 1/4 drive, I recently purchased some magnetic torx bits, the best thing since sliced bread, took the new housing apart and and cannibalised the the new core with seal and cap, job done, then discovered the Silicate bag in the expansion tank had ruptured so ended up having to back flush the heater matrix with a jet wash.

Just now, Stevey Y said:

Hi gents, in the recent cold snap the heater would not really warm up for a couple of hours even after driving for most of that time, finally ran it down to a lazy thermostat which was just staying open more than desired so consequently it only got what I would class as really warm about an hour before I booked off for the day, a good quality replacement stat core is about £60 but Audi only sell it as the whole pipe with a new core about £90 so I went for that considering my existing unit had done 180k so therefore I could expect at least that again, now begins the horror of replacement you have to take the inlet manifold off to get at it so I opted for the cheat and unbolted the old thermostat housing its only three torx screws and an extension bar all 1/4 drive, I recently purchased some magnetic torx bits, the best thing since sliced bread, took the new housing apart and and cannibalised the the new core with seal and cap, job done, then discovered the Silicate bag in the expansion tank had ruptured so ended up having to back flush the heater matrix with a jet wash.

This is what you have to remove to replace the whole thing. The other picture is the new pipe unit minus the thermostat but please note the three screw holes on the right for the screws, and last but not least the rubbish silicate bag, what soon thought that was a good idea is anybodies guess.

why are thermostats hard to do on some of our cars like my audi a4 2011 2.0 tdi.they used to be so easy to do in days gone by