Oil Pressure Dropping to 0

Good news! Thanks for the update, so many folks never report back.

Just a quick update on what we found out. It was the oil pressure sensor. It had broke open and was leaking at the base of the sensor. Replace this and pressure is back up and no more leak.

newman fulltimer wrote:
if you are running a frame filter it can cause that.use a wix or purilater filrer

Please explain how an oil filter can cause the hot oil pressure to go to zero at idle.

I think it sounds like a sending unit failure. I don't believe the oil pressure is possibly dropping to zero because if it was that engine would be clattering like there's no tomorrow.JMHO. Put a mechanical gauge on it and see what it says.

Any oil puddles under the truck? Other than the normal oil cooler lines? I am sure it is just the sending unit, but hooking up a mechanical gauge would be the best way to find out if you have a real issue. Or, buy the time you pay someone to do that, they could just put a new one on.

I'd get that ticking checked out though. The roller lifters are known to be issues and could be a costly problem if left alone.

boogie_4wheel wrote:
On that era trucks (at least with the 5.7L and standard pickups), there was an oil pressure switch that would command the fuel pump to run. So if you lost oil pressure, the fuel pump would stop. I wonder if the 454/7.4L is the same... If you start it cold, then shut if off, can you hear the fuel pump run for a few seconds (even with the key off)? I ask this because the truck continues to run without oil pressure; the pressure switch should open and stop the fuel pump. In your case a bad sending unit or bad gauge in the cluster. I assume you get the 'Check Gauges' light.

+1 on running a mechanical gauge and verifying oil pressure.

I have only gotten the check gauges light once.

On that era trucks (at least with the 5.7L and standard pickups), there was an oil pressure switch that would command the fuel pump to run. So if you lost oil pressure, the fuel pump would stop. I wonder if the 454/7.4L is the same... If you start it cold, then shut if off, can you hear the fuel pump run for a few seconds (even with the key off)? I ask this because the truck continues to run without oil pressure; the pressure switch should open and stop the fuel pump. In your case a bad sending unit or bad gauge in the cluster. I assume you get the 'Check Gauges' light.

+1 on running a mechanical gauge and verifying oil pressure.

Test with mechanical Gauge or You might be able to check yours with scan gauge since its ODBII. I know my code reader would show it. Could be cluster gauge going bad. My Old TV 93 K2500 Suburban, Friend bought it from me and is still towing with it. The dash gauge started to do the same thing, Tested with mechanical and Oil Pressure was OK.

No noise other then the Chevy tick. It has been there sense I have owned it. Nothing new.

You need to test it with a mechanical gauge. If it is the engine it could be a plugged pickup screen or bad cam bearings. You did not mention knocking which would point to bad rod or main bearings.