I have had a problem with my thermostat for a while now, and the cam belt is not due for change for a couple of years. I know that I can change the 'stat in a weekend, but after reading many posts here and elsewhere about new stats failing early, I looked for a solution The best write-up I have found is here Diesel thermostat definative answer , which, although over a hundred pages, is worth reading. Scrag, on the B6 forum has also had a look at this, and used a Renault 5 type 'stat here 2.5tdi changing thermostat - whats involved? I have gone for a more expensive, maintenance friendly solution - a remote thermostat. I sourced the manufacture of the housing from Classic Mini Parts | Titanium Components | Force Racing. Carl was a great help, and produced a nice bit of kit. I decided to fit the housing and 'stat in the top hose, using the coolant return to provide flow past the bulb. Here is the unmodified hose The recommended 'stats were from a Suzuki Swift, 1, 0 or 1.3 litre, 44mm OD, part no 10/84-02/89 for 82 degrees, part no, 03/89-12/03 for 88 degrees. I bought the 88 degree one. I then fitted the stat into the housing and screwed the halves together. This took a bit of fiddling, as there is a 'jiggle' pin that aids air removal that you want to keep at the top - it can just be seen here by the 10mm outlet There was more pratting about with sealing - I use a green pressure plumbing sealant - and then the unit can be fitted I then left it to idle whilst I checked for leaks (and rectified them!) and then the test - I have now ran the car about 100 miles, and it stays bang on 90 degrees.