If you are going to remove the old thermostat housing and fit it to the new water pump check the seal - they have a habit of leaking along with the O ring for the pipe. ;)

Personally I'd fit a new 'stat, but each to their own. :D

I see there's a huge thread on this subject! My 2003 CDT's temperature never reaches the 9 o'clock position and fluctuates considerably wile driving. As far as I can see from here it needs a new thermostat. Is that the only possible cause, or does anything else need investigating as well?

Yes your thermostat is at fault.

You can see the actual temp via the on board diagnostic.

check the temp using the on board display, I think the technique is on this thread somewhere. if it is below 80 degrees, then thermostat is most likely issue. inserting the Renault 5 stat will be the quickest and easiest method of finding out if it is another issue with the cooling system. (although I cannot imagine what that would be to cause it to run too cool )

Wow, those were really quick replies! :bowdown:

I'll look up how to run the on-board display and check it out - many thanks to you both. :}

T-Cut done a thread on it http://www.the75andztclub.co.uk/foru...iagnostic+mode

And a video here ;) http://www.the75andztclub.co.uk/foru...d.php?t=185808

Thanks for the guide, it's easy when you know how! I ran the diagnostics and gave the car a quick run up the motorway for a few miles. The temperature stayed in the low 60s most of the time, with 67 the highest. That's a lot lower than it should be, so I'm guessing that confirms the thermostat not working properly.

On the plus side I checked the plenum drain and everything is nice and dry, and I gave my cloudy headlights a good rub-down and polish - still not perfect but definitely improved.

I see there's a system here for thanking other posters, but I can't work out how to use it... :duh:

I believe once you have reached 10 posts the clicky button will be available to use for thanking others..

I have recently changed my thermostat out as I had to do the water pump and it's a bit of a pig of a job to be honest even using the excellent guidance on here. Being ambidextrous and a contortionist would be a huge bonus but for us lesser mortals the key is ensuring that your trolley jack can give enough lift when raising the engine so you can get to the bolts easy enough. Also having an E8 torx spanner comes in very handy if you don't have the lift and can't get enough room for sockets.

If it's just the thermostat at fault then if I were you I would just do the in-line mod for the same result needed.

Unfortunately I don't have the facilities for doing any real work myself, so I'd have to get a garage to do it. As I only bought the car recently I want to get a good service booked in, so my plan is to get the thermostat done at the same time. My local garage is pretty good, but can anyone recommend a Rover specialist near to Southampton?