Hello, done a few jobs today on the car including trying to work out where coolant is leaking on the passenger side. I can see it dripping through the under tray and immediately thought either the corner of the radiator is leaking or the bottom hose but it looks like it is the fan temperature switch where it is leaking. The copper is also quite corroded so I am thinking while I am doing it I might as well change the whole thing. Looking on ECP they are about £16 and the image shows a washer which hopefully it comes with?

Onto my actual question I have noticed there are 2 sensors, one appears to have 2 pins and the other 3. Which will I require on my 2001 1.4 MPI? Also, it looks as though the required spanner size is 29mm but it is so tight to get to. Any tips for the easiest way to remove and refit?

Should just need the washer/ptfe tape on the threads. Wouldn't worry about it not looking too pretty unless you're entering concourse contests

Thanks anewman, I have ordered some washers and also have some PTFE tape so I will probably do both and cross fingers! Any tips for the easiest way to get to the thing? Not sure it's possible from above without removing the battery etc... but may be wrong and from underneath there seems to be limited room for a spanner and plenty of pipes in the way.

I haven't touched the one on my car, but it looks reasonably easy to get at from the gap in front of the engine. That's how I'd try to get at it first. A deep socket with a ratchet wrench would probably be the best tool to use.