My oil pressure gauge is floating left to right....

oil pressure sensor, low pressure due to dying pump. or blown gasket causing the pressure to leak out. Check the easy ones first like the sensor. Good luck

How much below 30 is it dropping? Oil pressure when in DRIVE at idle on a hot engine, is NORMAL at around 18 to 20 Psi. The warning lamp does not come on until around 7 Psi.

With that said, the oil pressure switch (for the light) is located on the lower left front of the engine. The fuel pump oil pressure switch and sender (for the gauge and fuel pump operation) is on the lower right front of the engine.

Not the oil level sensor , Could also be the gauge is bad . You could try buying a used cluster at automotive salvage yard for $20 - 30 buck . Had a problem with chevy cavalier with the temp gauge showing overheating , just started the car so i know it wasn't overheating . Changed instrument cluster , the gauge work normally . You could also check the oil pressure with a pressure tester . Screws into when sensor screws into . Videos on youtube . How To Check Oil Pressure EricTheCarGuy

It sounds like oil pressure switch is bad. You said you changed? To clarify, your oil pressure switch is also a safety item that shuts down ignition when oil pressure drops. Try an oil pressure gauge (hand held) to relieve your nerves about engine seizure. Make sure you're not getting to much fuel in engine also, that will dilute oil to a thin viscosity and show low oil press.

let vehicle reach normal operating temp. remove oil pressure sensor replace with manual oil press. gauge run engine and monitor oil pressure go from there dependent upon findings

normal - pressure drops off at idle and increases as engine speeds up.

I have this same problem with my 2002 trailblazer; however, I goofed up and had a mechanic look at it, since I was perplexed as to what was going on with it. He told me the oil pump needed replacing and it ended up costing me around a $950. Needless to say, it still happens. A grand down the drain - it wasn't the oil pump. The oil level is always good. This generally occurs when I've run the vehicle for a while and then come to a stop. It occurs quite often during the spring/summer and doesn't happen all that much during colder months.

You need to replace the oil pressure sending unit, this is what tells your gauge what the pressure is. For future information if your oil pressure drops again and its a real failed oil pump within a few minutes you will internally damage the engine. I would get a new Oil Pressure Sending Unit. Let me know if you have any questions.... Thanks!

If you don't hear any ticking or knocking while the pressure gauge drops, the problem is probably a failing "oil pressure sensor". If you do hear a ticking or knocking, the problem is probably a failing "oil pump".

If you feel a difference in the vehicles performance it's probably not the sensor. Change the oil, and filter. Check the oil for metal flakes, shiny specs floating in the oil. Fill it back up one quart short. Add a quart of transmission fluid. Tranny fluid is a detergent, it will help clean any blockages and build up. Drive it for a week. Then change the oil again. If that doesn't fix it, you might have to drop the oil pan and clean that out. There should be a magnet in the pan. This collects metal that will harm your engine. Make you you clean it and put it back. Check the oil pickup, remove it and clean it out. Once you drop the pan, you will have access to the oil pump and it's sensor. Check them out to.