is it safe to drive?
 

Long story short I recently replaced a defective oil pressure sender unit because of a super bouncy gauge, now with the new unit I have 0-5 pressure in drive parked when hot, 40 when its cold. Idle speed gives be about 10 psi.
I have had no issues with the car driving or anything. the gauge moves with the rpm and stays at @ 40 at cruising speed. Im planning on taking the car to a wedding about 2 hours away next week and am hoping this is a gauge issue. I checked the oil today it was a little low, the temp gauge is reading @185-195. I cant right away verify with another gauge, I don't have the means to do so. Suggestions? Where to start looking?

Thanks in advance, Pete.

Not fun having a spun rod bearing on a road trip.

Been there, done that.

I'm having the exact same issue. My next move is to check with a mechanical gauge. I'm not driving the car until it's sorted out in case it is a weak oil pump.

engine has @ 5000 miles on the rebuild, im running 10-40 weight oil. im thinking the gauge could have been damaged from the last sensor bouncing it around so much I dunno.
Filter and oil were changed last year and I only put @ 600 miles on the car since then.

What did you use on the new sending unit threads?

Symptoms posted sound like oil pressure relief ball stuck partially open. Stuck or piece of trash wedged in it.

I've got lucky a few times by changing to heavier oil so the pump would push the ball back and flush whatever had it stuck out.

More times than not, had to R&R the pump to fix it.

I would have to verify with another gauge before doing much more driving.

I just went through something similar. Here is the link to the thread.

http://forums.maxperformanceinc.com/...d.php?t=791947

Some filters are better than others too. Oil pressure can vary with filters.
Sounds like the bypass is stuck.

So after work today I started it up and the pressure was great when cold but as it warmed up it gradually dropped to 20 at idle and 0-2 in drive, it comes back up as I rev the engine. I looked into the oil filler hole on the valve cover and oil is flowing it was hard to tell once it was warmed up if it was still flowing, ugh.

I only had a relief ball stick once I messed around with it when I discovered it after work on a Friday and couldn't get it unstuck the next morning I went out when it was cold and started it up and put the pedal to the floor ... The combination cold start cold oil lots of bypassing knocked the ball straight again and I had normal pressure again... Your results may vary

If you have no gold flakes in the oil i would drive it as is.at idle 20 is fine.

Your pressure at hot idle in drive is a little worse than I have. Still comes up quick with RPM. Get a mechanical gauge to confirm the pressure. I think it is generally agreed that mechanical are more accurate. I like the old SW 270 degree sweep that are only 80psi max and have more needle movement at the low end. Very few of us are running pumps where you need a 100psi max anyway.
I attribute my problem to a rebuilt engine where the crank was polished and has std bearings. Clearance is at spec max. And then I have both rocker stud and push rod oiling to top end. Probably loose a little pressure there. But pressure comes up quickly with RPM so with 12-14 psi at idle I just drive on.

I broke a ring land of a stock flat top piston and some grit entered the relief valve. I took off the head and did an "in chassis' removal of the piston. At which time I fixed the problem with the oil pump. The symptoms were the same, low oil pressure when idling and the pressure went up with the rpm. The rod bearing was fine but I replaced it anyway.

Did you say it has 0-2 psi when idling in drive?

You MUST QUALIFY your sender and gauge first. You don't know what the heck is going on.

Remove sender from engine and connect wires back to the car. Sender and ground.
Use air pressure to apply to senders oil port. Varying pressure should follow on the compressor regulator and oil gauge.