Car taking an age to warm up

[Itguy]

Also - can someone check if part number 06F121111F is the right one for my 05 plate early GTI?

Does anyone also know if these thermostat housings have ever had any revisions (a bit like the DV's have?)

I just wonder if my car has an early version that had problems that was then replaced by a revised version on the later cars, hence the different replies from people.

[Human Joist]

Don't forget though were only talking about water temp. And the water temp won't get hot until the engine warms up as thermo won't open. If it opens too early in effect you will be taking the heat from the oil and engine and cooling it therefore stopping the engine reaching its correct operating temperature quickly enough which is the reason I would not worry if the thermo switch opens straight away the engine will have to be running for a lot longer in order to get the operating temp so it's less likely to heat up on your journey. Sorry I should have explained further. It does not matter if the water takes longer to warm up as long as the oil and engine don't get too hot as a consequence. As long as your engine is not overheating the thermo should be working.

At least this is my take on how it all works.