HELP... oil pressure gauge still at 0 !
 

I must say I am pretty disappointed today.. I finally got all the parts I needed: Oil pan, Gasket, Oil pressure sender and Oil level sender. Originally, the problem was my oil pressure gauge dropped to 0 last week and I was told it’s most likely the oil pressure-sending unit. So I got underneath the car and found that there was some oil leaks around it as will as the oil pan was bent and decided to replace both. I decided also to replace the oil level sender since I saw some leak from its connection side.
So, and to make long story short, I replaced all the above and all went well except that the oil pressure gauge still set at 0. I ran the tests as recommended on the wire and don’t think it looked good. So I seem to have either a bad wire harness or bad gauge. Which one is it? How can I know if the car is safe to drive without knowing if I have a true oil pressure or not? The car drives fine and I hear no engine noises etc.

Need help from the experts out there on what to do next? Any “quick” check I can do easily to determine oil pressure without having to tap into the line? I just wanted to know if I should drive the car or have it towed to the shop?

Pull the oil filler cap (carefully) while running and see how the "wet" the top end is (and maybe you). Won't tell you pressure, but gives you an idea. You can remove the oil pressure sending unit and screw in a cheap mechanical oil gauge from Pep Boys (they have the metric adapters for same also). Just to diagnose. A cheapie oil gauge with adapters ~ $20.

Something like this http://www.autobarn.net/eqoilpreselt.html

and this:

http://www.autobarn.net/eqoilpresgau.html

I would strongly recommend not to run this engine until you are totally convinced there is oil pressure.
Years ago (many) I thought I had a deffective oil pressure gauge/sending unit on a Volvo P1800. Since I was on my way to work, I simply forgot about it and drove the car.
5 miles later, I knew I had no oil pressure. The engine seized.
JackD

I wanted to fix my oil pressure gauge also. Mine is stuck at 3 at all times, I have never seen it go below. I think it's my sendign unit, but I've been driving the car like that for 9 months and no problems so far. I want to get it fixed eventually, I like when everything works in my car.

Have to check the manual which part does what.

xp

That's how to check it from The Manual:

Thank you all for your feedback.

Golden Rule,
how much pressure i am supposed to get when i hook up the mechanical oil gauge? in other words i guess i need to know what is a 3 bar equlas in PSI?

1 bar =14.5psi. Bar refers to barometric pressure at sea level, which is 14.5psi.

So 3 bar = 43.5 PSI
 

I tested the oil pressure unit and its connecting wire and i don't get the readings described in the shop manual attached by Myarmar above. So that leaves me to believe either it's a harness problem or gauge... worst case a true oil pressure issue (hope not!) i decided to take the car to the shop (tow it) first thing Monday as I am starting to get into areas above and beyond my mechanics abilities. Thanks guys.

Fixed!
 

Had the car towed in to an independent shop. The guy tested the oil pressure with a mechanical gauge and there is strong pressure. That was a relief. He the removed the cluster and tested the wire connection it tested fine he reassembled the cluster and the problem went away! Sounded like a bad connection at the cluster side with oil pressure sender wire. i hope that was the end of it. Cost me $68 (1 labor hour + $55 tow). Happy it wasn't pressure problem! Had to tow it in for a piece of mind. Thanks to all your help.

Re: Fixed!
 

Smart move. Priced out an M104 engine lately? Glad it worked out for you...