testing Oil pressure sender and gauge?

[duncan]

heading back in Sunday after the first run for 'some time' the oil pressure gauge went to 0 - didn't see it go there, but one minute it was normal and the next it was 0.

it was so far 0 it was effectively off.

the engine, Yanmar, also has an Oil Pressure warning light/buzzer and these remained silent - the engine bay wan't full of oil either. It ran fine (but I kept at 1000rpm in the harbour anyway)

so, armed with basic logic I have either -

1. duff gauge

2. duff sender

3. duff wires/connections

any suggestions as to how to check any of these, presumably with a multi meter, appreciated ? (and no, I don't have a dual installation)

 

[David2452]

You can only really use the multi meter to test the sender, here is a link to a basic trouble shooting flow chart and a resistance value chart, it will give you a decent start, I searched high and low for a test instrument to check gauges and ended up making my own with a 0 - 300 ohm variable resistor.

http://faria-instruments.com/site_manuals/IS0100_ApxVII.pdf

http://faria-instruments.com/site_manuals/IS0085E.pdf

 

[duncan]

excellent - thank you

 

[mawm]

heading back in Sunday after the first run for 'some time' the oil pressure gauge went to 0 - didn't see it go there, but one minute it was normal and the next it was 0.

it was so far 0 it was effectively off.

the engine, Yanmar, also has an Oil Pressure warning light/buzzer and these remained silent - the engine bay wan't full of oil either. It ran fine (but I kept at 1000rpm in the harbour anyway)

so, armed with basic logic I have either -

1. duff gauge

2. duff sender

3. duff wires/connections

any suggestions as to how to check any of these, presumably with a multi meter, appreciated ? (and no, I don't have a dual installation)

I had a very similar demise of my oil sender unit. One moment working, and the next not. I had a mechanic look at it. He tested the resistance in the unit (multimeter) and it was incorrect, later he inserted an aneroid measuring device where the sender attaches to the block. It measured the correct pressures. His diagnosis was that the sender had died, as I understand it was probably due to wearing through the solenoid at the point where the pressure sensor has rubbed for years. He put in a new sender unit and after all the air had been evacuated the readings were back to normal. The cost of a new sender is not much - NZ$ 120.

 

[duncan]

thank you for the response - food for thought