FAST LS1

iTrader: (2)

So the oil pressure guage is at zero.
When I'd take the key out of the ignition, the guage would rise to about 20-25psi, then as soon as I turn the key to run, it would drop to zero. I started it a 3-4 times and on the last try I heard ticking and turned it off and left it set
Full of oil, I checked that the first time I cranked it, and it started and still read zero.

The fact the guage moved off of zero while setting makes me think it's not the guage, and the slight ticking on the last attempt is sickening. I probably should have said **** it and left it set the first time it read zero, but I was stubborn.
Leaving work the check guages light came on. I saw zero oil pressure, cut the engine instantly in the middle of the road. Stopped, checked, and started it back up and it read 40-45psi, so I thought the guage was just going out. Damnit.

So know to diagnose the problem, because from previous posts on the subject I know it could be any number of things.
1) Sending unit is bad. I haven't done an intake swap though to hurt this sensor.
2) Oil pump is bad
3) Spun bearing

I guess I'll be riding the motorcycle and borrowing one of my parents cars to get around, so I'm ok there. I can afford to have the car down 2-3weeks if neccessary, but I need to figure out the problem quick in case I'm ordering a forged shorblock instead of an oil sending unit.

conan

iTrader: (5)

I'm going to say go with your 1 and 2 diagnose, if you spun a bearing it would e a very loud ticking/knocking. You could look on the bright side change the sending unit ---> ls6 intake time. Change the oil pump---> Cam time

FAST LS1

iTrader: (2)

I have the LS6 intake and 01+ injectors and fuel rail sitting in the basement.
I just don't have a couple thousand dollars laying in the basement to put a new longblock in the car.
If that's the case I'd probably get a forged shortblock, heads, and mild cam, but I'd rather not have my only car down for the rest of the summer, and spend tons of money on it.

SporkLover

iTrader: (2)

After you start it does the gauge move to a normal oil pressure? So far everything you described, my car goes through, except the oil gauge moves after it starts.

conan

iTrader: (5)

If you moter didn't eat it self why would you need a new long block? If you already have a new intake get your self a new sending unit and do it all at once. If the sending unit doesn't fix your problem go after the oil pump. The cam was just a sudgestion because your in the moter that far why not get some extra pony's if you have the $$.

FAST LS1

iTrader: (2)

I'm going to see if I can check to see if the existing sending unit is working. If I'm going to have to replace the pump I'd like to do a cam install. The only problem then becomse if the pump actually died or I'm getting no oil pressure from a spun bearing.

theblur98ss

iTrader: (71)

Verify the gauge is working first....if it's working then I'd swap the pump and check the oil for metal and go from there.

FAST LS1

iTrader: (2)

Sounds like the best plan.
How do I go about checking the sensor?
Can I use a multimeter somehow without cranking the engine?

This could be potentially be really bad. Searching I've found most people with zero oil pressure had spun bearings.

theblur98ss

iTrader: (71)

What I did was drill and tap the little fitting above the oil filter and hook up a gauge. You will have to start the car to check the pressure though.