Right, so my cooling fan is quite temperamental so im going to swap it.

What size is it?

Should i get a second hand one?
Should i get a universal one?
Should i get an aftermarket one?

If anyone could find examples that would fit my model that would be great!

If you would like to save some pennies then I suggest going second hand from the scrappy. Just take one off another MK2.

Get a scrappy one hooked upto a battery to test it

If the fan works listen for bearing failure or grating noise or poor performance

If the fan seems to move sufficient air - give a whirl in your car (see what i did there?)

ziggy