2007 Chevy Silverado oil pressure gauge fluxuating, setting off computer on dash reading "engine oil low" also warning bell sounds. Thanks!

Have you checked with a mechanical gauge to see what your pressure is? You might actually have low oil pressure.

in a shop we ignore the dash gauges and use REAL gauges.
we attach a real gauge to the sender port. on engine block.
and read the true pressure.
the lamp on most cars go on at 3 to 5psi.
this is catastrophic failure. that low.

my guess, is you let oil drop and you wrecked bearings.
but let the real gauge prove that , dont guess.

If oil level in engine is at proper level, I wouild suspect oil pressure sending unit, does vehicle have an oil psi gauge on dash,,,if so what does it read. if oil psi reads well then it may be an oil level sensor. if you have access to a manual oil pressure gauge, you can remove the oil psi sensor and install manual gauge to get a true reading of what oil pressure is while running. if manual gauges shows low psi, then you may be looking at an oil pump.

DW Mylin

see this tips and fix it. God bless you
The oil pump supplies oil to lubricate your engine. If the oil pump is worn or is not turning, the engine will suffer a loss of oil pressure, which may result in engine damage or engine failure.
The first sign of trouble may be a low oil pressure warning light, a drop in the normal reading on you oil pressure gauge (if your car has one), or the appearance of ticking or clattering sounds from your engine.
As a rule, most engines only need about 10 PSI of oil pressure for every 1,000 RPM of engine speed. Oil pressure will read higher than normal when a cold engine is first started because the oil is thick. Oil pressure will gradually drop as the engine warms up and the oil thins out. So normal oil pressure on a warm engine cruising down the highway is typically 30 PSI up to 45 PSI.
SYMPTOMS OF OIL PUMP TROUBLE
The first thing you should do if any of these symptoms occur is to stop your car, turn off the engine, let it sit for a few minutes, then check the oil level on the dipstick. If the oil level is at or below the ADD line, add a quart of oil to bring the level back up to the full mark. Add as much oil as is needed to raise the level to the full mark. Then restart the engine. If the warning light remains on, or the oil pressure reading does not climb back up to its normal range, or the engine noise does not go away, you may have a bad oil pump.
The other possibilities include a bad oil pressure sending unit, or a problem with the oil pressure warning light circuit or oil pressure gauge.
OIL PRESSURE SENDING UNIT
If the engine is NOT making any unusual noises and seems to be running normally, and the oil level on the dipstick is FULL, but you are still getting a low oil pressure warning light or low gauge reading, the fault could be a bad oil pressure sending unit.
The oil pressure sending unit is mounted on the engine block. On some applications, there is a spring-loaded pressure-sensitive diaphragm with a switch inside the sending unit. This switch completes the circuit to the low oil pressure warning light if oil pressure drops below a certain threshold. The unit may stop working if the diaphragm inside fails, if the switch is stuck, if the small hole that allows oil to enter the sending unit becomes plugged, if there is a loose, corroded or broken wiring connector at the sending unit, or there is a fault in the wiring circuit between the sending unit and warming light.
On vehicles that have an oil pressure gauge (electronic, not mechanical), the oil pressure sending unit has a small rheostat inside that sends a variable voltage signal to the oil pressure gauge when the diaphragm moves. A worn spot on the rheostat or any of the other problems just described for the simple pressure-type oil pressure switches can cause a problem.
FORD'S FAKE OIL PRESSURE GAUGE
On many Ford vehicles that were built from 1980 through the 1990s, the oil pressure sending unit has two switches, a low pressure and a high pressure. These vehicles also have an oil pressure gauge, but the reading on the gauge is not a true indication of real oil pressure. As long as the pressure to the sending unit is between high and low, the gauge will read normal. If oil pressure drops and trips the low pressure switch, the dash gauge will now read low. Or, if oil pressure goes up and trips the high switch inside the sending unit, the dash gauge will read high. Consequently, don't rely on the oil pressure gauge for an accurate reading in these vehicles. It is only a gross indication if the oil pressure is low, normal or high.
OIL GAUGE PROBLEMS
If the engine is NOT making any unusual noises and seems to be running normally, the oil level on the dipstick is FULL, and you have replaced the oil pressure sending unit but are still getting a low oil pressure reading on the dash gauge, the fault could be in the wiring circuit between the sending unit and gauge, or the gauge itself might be bad.
Check the wiring connections on both ends as well as wiring continuity between the sending unit and gauge. If no wiring faults are found, hook up a pressure gauge directly to the oil pressure port on the engine and check oil pressure with the engine running. If the engine-mounted gauge shows normal oil pressure but the dash gauge is reading low, the problem is a bad dash gauge.
On the other hand, if the engine-mounted pressure gauge reads low and you have done all of the above, chances are the oil pump is worn, or it is not picking up enough oil because of a restriction or blockage in the pickup screen in the bottom of the crankcase.
OIL PUMP PICKUP PROBLEMS
The pickup tube has a screen on the end to prevent large chunks of anything bad that ends up in the crankcase from being sucked into the pump. But we are talking BIG chunks of debris, not normal wear particles or carbon or dust or other microscopic-sized abrasive particles that can cause pump wear over time.

This does sound like the oil pressure sending unit is going bad. Had an 02 Vette with the same issue.

The location of the sending unit is behind the intake manifold. You will unfortunately have to remove the manifold in order to replace the unit, but this is easy enough as the intake manifold is as simple as they get on the LS1 engine.

Hope this helped!

It could be the sending unit. If the truck is low on oil it will cause something similar. Be sure the oil level is topped up. The only way to be sure it so measure the actual oil pressure at the engine with a proper gauge..

If its reading low oil pressure I would first change your oil and filter.A clogged oil filter will cause your oil pressure to drop.Also remove your pressure sending unit and hook up a direct oil pressure guage to see what your actual pressure is.Its very possible that your oil pump could be bad.Those would be the most probable reasons for low oil pressure.The engine shut down means that your your engine has a fail safe to protect your motor from blowing up.

Replace the oil pressure sending unit its giveing a false reading . The problem is when the engine is cold the oil pressure is low and it takes a little time to build up whem cranking the engine and that sends a signal to the computer PCM /VCM what ever but your 40 to 60 lbs oil pressure is graet its ideal .The unit switches when the oil pressure is high enough to trip the switch inside the sending unit and that is sent to the vehicle control module

The fuel pump on that model runs through the oil pressure switch so that if the truck looses oil pressure,It kills power to the fuel pump to prevent engine damage.you need to find the cause of the low oil pressure reading(possibly a bad oil switch).That would be the cheapest place to start,or have it checked with a mechanical gauge.Good luck,
ChevRev

Are you referring to the oil pressure gauge on the dash? If so, that is most likely the oil pressure sending unit having gone bad. The sensor runs about $40 - 50 (at least the last time I had to replace one on that engine). They are not terribly difficult to replace and I believe its a three wire sensor located back side of the engine, on the passenger side area. Its in a kind of tight spot and takes a bit to get it completely screwed out, but it can be done.

When they go bad, they typically will cause the gauge on the dash to read maximum oil pressure. You should be okay to run like that until you can get a new sensor as long as it is reading maximum oil pressure on the gauge and not low or no oil pressure on the gauge.