Mk3 Cavalier Owners Club | Vauxhall Cavalier Dot Com

1993 Cavalier V6. Can anyone tell me where to get a level sensor for the radiator header tank? The one on my Cavalier V6 just clips to the outside of the header tank and is currently going into a low level condition erroneously and randomly. The only level sensors I've been able to find online are immersed in the header tank coolant.

I am going to sound stupid here, but are you sure it is the coolant header tank level sensor?

I have looked at EPC and ECat24, and both only show the "float from the top" sensor.

Part number 90423328.
Item 10 in the image below.



(Courtesy of Ecat 24 and postimages)

From memory the sensor formats are -

Brake Fluid =
Two wire sensor mounted vertically in the cap.

Coolant header tank sensor =
Two wire sensor mounted vertically in the cap.

Winscreen washer fluid =
Two wire sensor mounted through a rubber grommet in the side of the washer fluid bottle.

Oil level sensor =
Two wire sensor mounted via a metal bolt-on assembly on the side of the oil sump.

The sensor you describe sounds like the winscreen washer fluid level switch.

Part numbers -
6 for switch
90346055
7 for grommet
90276310

Many thanks for the informative reply, but this is interesting.
My header tank looks different from the one you show and has always had a plain cap - not one with a sensor in it. The only header tank sensor I can see is definitely clipped to the outside of the front of the header tank just behind the battery. The header tank actually has a moulded in housing to take the sensor. It is located at just below the normal cold water level point - so I guess it operates by some sort of capacitance measurement . The windscreen washer bottle is actually under the wing - behind the front bumper - with only a filler neck within the engine compartment . So the level sensor on this is on the bottle below the wing - and I know this is working OK. Maybe the Cavalier V6 had a different arrangement for the header tank level than all the other Cavaliers?

Indeed, the Cavalier V6 header tank in unique and therefore very hard to find these days.
The part number is 90448876
and it looks like this:



I believe that the sensor is integrated into the tank itself and you cannot buy it separately.

Thank you for that clarification, though the picture shows the sensor orientated in the opposite direction to the one on my header tank! The sensor does unclip from the header tank housing but I would not be surprised if it was only sold by Vauxhall as a complete unit with the header tank. Although this failed sensor is a minor issue (I can live with it) I would be happy to buy a complete header tank and sensor. Does anyone have one for sale or know where to obtain one?

James is correct they are very hard to find but crucially you can find the very same header tanks on various Sabbs so check out a sabb breakers . That's where I got my header tank from for my v6

I have found that new header tanks for the V6 are still available from a supplier in Germany - opelteilekrause*otk - via eBay. They are supplied complete with the level sensor though this appears to point in the opposite direction to the ones used in UK V6s, which may need wiring to be extended or re-routed. They do come at quite a price though - £131 plus carriage. Still, I imagine that when Vauxhall in the UK supplied these they wouldn't be much cheaper!