Oil pressure guage off scale

[richardworrall]

On the upside my car passed the MOT today, on the downside it came back the with oil pressure guage completely shooting to the end of the dial on switching the ignition on, it used to be fine until today. It wont settle down either once the engine is running.
Whats the likely cause and where would i find the relative connections on an 8v.

[L337 calibra]

Well the gauge will shoot right over if the wire is disconnected, could be loose at either end, check the plug on the back of the gauges or at the sensor on the back of the block by the oil filter (not to sure of the exact location but it is around that area)

If it all checks out and looks connected check for continuity between the sensor wire and the plug, oh BTW the one you want to look at is the one thats secured by a nut.

Andy

[Vanguard]

Richard,
All Vauxhalls with dash mounted oil pressure gauges use the same oil pressure sender unit. With my V6 Calibra it was the sender unit which failed - these are £120 new from Vauxhall but should be available from breakers for about £25.
On the V6 the sender unit is located on the driver side of the engine and is viewable by taking the drivers side wheel off. It's a round thing about 5cm/2" long with two wires coming out of the end. My local Vauxhall dealer showed me where it was located and what it looked like. There is a 19mm nut on the back of the sender unit which, on my car, was virtually impossible to shift. Although you can get a 19mm spanner on it you can't get any leverage. I eventually got a chain wrench on the sender unit and that eventually started it moving. Oild will come out of the hole, but not quickly, so you'll need to have the replacement part to hand.

[RobbieV]

Richard please check thread dates before replying ......... thanks