L28 oil pressure question

[Mr Camouflage]

I got a 240K recently. It has a L28 in it.

Oil pressure gauge reads 0 all the time. Doesn't move at all when the ignition is switched on or off.

I suspect the engine has oil pressure, it would probably be dead by now if it doesn't. But i want to be sure before i start driving it regularly.

So i'm guessing either the gauge or the sender unit is faulty.

If I take the lead off the sender and ground it should the oil gauge go up?

Does the resistance of the sender unit go up or down as oil pressure increases?

Cheers,

Craig.

[Virto]

Assuming it's a factory sender, you should be able to take the lead off and ground it. When you do, the needle will probably rise to the top...this indicates a faulty sender.

If you get nothing at all when you ground it, you've got a connection failure somewhere or a toasted gauge.

[Mr Camouflage]

Thanks. I thought the gauge should go up if you ground the wire. I think the is a problem with the guage wiring somewhere.

I got the multimeter on the sender last night. It was reading about 250 to 300 ohms when off, and went to 100 ohms at idle when I started the engine.

[beandip]

The factory gage and sender are not that accurate , they are really just an indicater of oil pressure . I bought a cheep mechanical oil pressure gage for like $12.00 and installed it just so I could varify zero pressure reading I was getting from factory origional gage. I am running 12psi at 700 RPM and 50 at 2K and above . I am going to replace the sender and go from there. I dont want to run the aftermarket gage . I have peace of mind now though. The same holds true with the temp gage , with it , check the coolent temp with a candy thermometer to determine what the actual temp is when the gage is showing mid range or what ever . Gary