Leak from radiator

[Pete]

Hi,
I have a 2002 Polo 1.2, 3 cylinder with 75K miles.

I noticed a small leak coming from what looks like a sensor that fits on the right of the radiator as you look down into the engine bay from the front of the car.
What I think is the sensor is like a large bolt with wires coming from it.

Is this the water temperature sensor?

Is a leak from here common?

Does the sensor thing just need tightening up? If so, how do I tighten it as I don't think you can fit a spanner round it.

Thanks in advance.
Pete

[alexperkins]

Welcome

That's the fan switch. It has a rubber o ring that can perish. Just needs removing and the seal replacing and all should be good if this where it's leaking. These radiators have been known to leak on the ends where the metal meets the plastic so be sure to check it's not that

[Pete]

Hi,
Thanks. Can't see how I can remove that fan switch without taking out the rad? Is it possible to do in situ by disconnecting the wires and putting a socket on the end?

Cheers

Pete

[alexperkins]

Yeah - you remove the plug then put a spanner onto it to remove or a suitable deep socket.

[Pete]

Hi Alex (or anyone else)

So, the fan switch is made of a metal nut part (about 27mm) which screws into the rad and attached to the metal nut type part is a plastic part with the wires coming out of it.

I tried removing the plastic part so I could put a socket on the metal nut part but there is no way of removing it.

How does it come off? Is there some sort of circlip? I don't want to break it.

Is it the complete plastic part that comes off or just the end of it with the wires coming out?

Thanks in advance.

Regards

Pete

[alexperkins]

Hi Pete

Just the wiring comes off. The triangular plastic part is part of the sensor. You'll need a 27mm
Open spanner to get it out

[Zeno]

Just removed and resealed my Radiator fan thermal switch.The nut is 29mm (I only had a 30mm open ended) sealed by a 22mm aluminium crush washer, the plastic side wall of the radiator has a metal insert. Working from underneath, I removed (dam plastic tabs ) the double wiring harness bracket to give better working room. Drained coolant.
To get at the connector release tab I needed to unscrew the sensor 1/2 a turn with the connector still on it so that I could get a screwdriver in the connector tab release opening, some silicon spray helped ease the removal.
The sensor was not tight, washer face had crud on it. All faces cleaned and reassembled with high temp exhaust silicon sealant.
All good.