Got a 1994 z28 with mild cam kn filter ram air intake msd ignition and headers not a bad car. Is the lt1 obviously with ttops t56 and 01 vette rims. Anyways my problem is good pressure at cold (30psi) start but within 15 minutes or at normal operating temperature ot drops drastically like to 5 psi ad idle. Any help would be appreciated I know I still need to check mechanical gauge on sending unit but what's my options. Oil pump. Sending unit. What else ?????? Thanks in advance
James

 

Verify with a mechanical gauge then consider options. It might just be the sending unit.

 

ok ya will look into checking it with the mechanical gauge and go from there

 

Well found my problem. Took to my shop hooked up snap on mechanical Gauge reads. Like perfect found a leaking sending unit. Also had vibration while driving thought bad ujoints found harmonic balancer was splitting apart so for $150 getting new balancer and sending unit both installed . Very exciting

 

A lot better than any alternatives you were thinking of, l'm sure.

 

Well was super excited until we pulled the old balancer off and found a coned crankshaft so still get to pull motor and doing an eagle crank kit new balancer oil sending unit all new felpro gaskets bearings and cleaning everything hooray right. Only positive is it'll be lotsa new unlimited mile 12 month warranty and only paying 1500

 

Beware of Eagle cast cranks. A stock LT1 crank is a better unit.

 

If it is then I will swap out then. Just got motor out yesterday so still time to make adjustments thanks for the heads up

 

And now the update lol started pulling apart and went with full rebuild plus adding flat top pistons and found crane cam gold roller rockers if all goes well will be picking up tomorrow. real high hopes

 

I have the same issue with my 95 z28 setting at 10 psi but I replaced the oil pressure sensor and it now drops to 0 psi and just last night when I come to a stop b4 my road home it had light knock but it wasn't consistent with the speed of the motor when I took off the pressure came up and the noise stopped could someone please give me some advice I'm obviously going to change the oil pump with a high out put pump what else should I be thinking about changing out while the motor is opened up?

 

Did you verify the pressure using a mechanical gauge, before replacing the sensor? Maybe a wiring problem, not a sensor problem.

But, with the knock and dropping pressure on stops, sounds like the oil pickup may have fallen off the pump.

Do NOT install a high flow pump. It is not required, and can lead to causing the stock oil pan to run low. You also do NOT need a high pressure pump, unless you have some heavy duty modifications.

 

Ok thanks I'll drop the pan and see if it actually fell off the pump

 

one of those inexpensive bore scopes that plug into a smart phone through the oil plug drain hole would be a very quick and easy way to determine if oil pump pick up came off.

Dropping the pan with motor in the car is not a small job

If pick up is still on and your oil pressure gauge is in fact right (read wiring & sensor also) and low oil pressure is still shown than your bearings are worn. Any type of new oil pump will not fix that

A "temporary" band aid would be use 10-40 or 20-50 oil....but that's just a temporary band aid

There is a NPT plug on block right above the oil filter adapter if you want to plumb in a known good mechanical gauge to confirm against the dash gauge

 

Hi Chimera, thanks for this information. Is there a photo you know of to show this NPT plug ?

 

Above the oil filter. Shoebox's photo:

http://shbox.com/1/aux_oil_port.jpg