I was getting the following error code on my wifes 1.4 vw lupo and the coolant seemed low. This would also explain why the car was running rich. (quite smelly)

wiki.ross-tech.com/wiki/index.php/00522

I cleaned out the old coolant, flushed and burped the system with 50/50 red coolant.

I also took out the G62 sensor and cleaned and put back and cleared the code. I checked the wires and notice that the black plastic tubing that held the wires had perished a bit.
The wires inside looked fine so I just taped up the small hole in the tubing with electrical tape, and mad sure it wasn't touching the engine block.

I'm going to replace the G62 sensor when the shops open.
www.eurocarparts.com/ecp/c/Volkswagen_Lupo_1.4_200...S

That error code hasn't poped up yet. (only run the engine for 5 mins)

I ran the car at 2k revs until the rad fan kicked in to get any air locks out of the system.
Now when the rad fan comes on at 90 degrees, there is a really loud screeching sound.

Is this coincidence or something I did? Could the sensor be causing this loud noise. I haven't got a new one yet, I removed the bottom RAD pipe to empty the system. Maybe the fluid could have go on something (nothing really beneath the bottom hose of the rad)

Coolant is just below the min line when cold and just above the max, when at this temp.

Do you know what it could be? I've check the rad fan and it isn't rubbing on anything. Is there anything else that comes on when the rad fan spins up?

I don't see how that noise can be related to fluid, unless it there is another pump that also comes on when the fan spins up.

It is really loud, do you think I should drive it to a garage or get towed