Oil pressure have a 1.5L SOHC - when hot -oil pressure light comes on & have rocker noise - need to know where the sensor is to remove & install master guage to check pressure. Also need to know what the pressure hot should be at idle. Thanks again, Chris Craig, Aruba, DWI

It could be that the valve clearances need doing, if that doesn't fix it then put a oil pressure guage on it and check the pressure,

MAY---May-be you really have low oil pressure.. The way this sensor works is when you turn off the engine it closes to ground.. and when you start the engine.. the oil pressure opens it and the light goes out.. SO.. if the wire going to it is grounded out somewhere between the sensor and the dash board the light will stay on.. 3 choices.. 1. bad sensor (even though you replaced it) 2. wire is shorted to ground.. remove wire from sensor while engine is running.. light should go out. 3. you actually have really low oil presure. next.. after you have exuasted #1-2. you can remove sensor and install a real oil pressure guage and see what the pressure really is.. If you have very low or no oil pressure..1. Check oil level.(probably should have done this first) 2.pull oil pan and replace oil pump.. while you are there check a main bearing and a rod bearing for wear.. worn out bearings will cause low oil pressure. If you have good oil pressure install the pressure guage permanetly and forget about light.

could be bad lifters or loose rocker arms, bad oil pump or low on oil, possible bad cam (but not likely)
first thing i would do is check your oil real low oil will cause this
if oil is fine check for oil pressure if oil pressure is low assume bad oil pump
if oil prssure looks good look for bad lifters or loose rocker arms

a mechanical gauge properly installed using copper line not plastic is a good idea ( plastic gets hard and breaks or melts if it gets hot)
do not consider turning off the light or the noise as it will hide a pressure failure
remember that the average driver doesn't look at the gauges while driving

could be a bad oil filter, plugged sump pick up tube screen, have a mechanical oil guage installed to ge an accurate reading, althoug i suspect if the engine is making noise it may be damaged, best to remove the oil pan for inspection, metal shavings in the bottom indicate serious problems

Maybe your engine is idling too slowly, If the revs are below say 700rpm the low pressure warning light could come on especially when the engine is hot.. If the idle speed is ok try a heavier grade of oil in the engine. Next try a new oil pressure sensor. It's got to be one of these things. Check the engine running temperature . An over-hot engine will cause the oil light to come on too.

When the pressure reads low, are you hearing any knocking or tapping noises from the engine? If so, you may have worn engine bearings. I'd check the actual pressure by having a mechanical gauge installed on it in order to determine the actual pressure (your gauge is electro-mechanical and not quite as accurate) If pressure is actually that low the oil pan must be removed and bearings, oil screen etc need to be checked.
The reason pressure is always higher at first is that when cold the oil itself is thicker...as it gets hot and thins out pressure will drop somewhat, but should not go that low. Only other thing that can affect pressure in that way would be either a bad sending unit (you will know that after testing) or gasoline contamination in oil (happens if an injector is not working properly)
Good luck with it!

Hello daebbers: My name is Roger and I will be glad to help you. I assume by the way your question is written you have no objectionable engine noise. I would suspect a bad oil pressure sending unit. To check the switch will require a mechanical oil presser test. You can buy a kit at any parts store. With a cold engine. Remove the oil switch from the block. Install the mechanical gauge. after all connections are tight start the engine. Note where the pressure is at. Observe the pressure through engine warm up. As the oil and engine warm up the oil pressure will drop. According to All Data information the oil pressure at curb idle is 6 psi. This would be a min. oil pressure. If the oil pressure is higher then that is great also. Any thing less you have a internal oil leak. This would likely be a bearing issue.
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change oil pressure sending unit. remove oil fill cap start engine to determine if oil pump is delivering oil to rocker arms. it it easer to tell if you remove one valve cover and then start engine. if rockers are not recieving oil change oil pump and clean oil strainer in oil pan

You may have a Faulty Oil Pressure Sender.
Here are some reason why your guage is bouncing:

• Corrosion or faulty electrical connections
• If the oil pressure gauge is pegged low after the engine is running, or is pegged high after the engine is running, or if there is intermittent illumination of an oil pressure indicator light, the sender could be faulty

You can find the oil sensor on the left hand side near the Oil Filter, as long as you don't hear your lifters ticking and making lots of noise. it's not your oil pump failing. 
Good luck and hope this helps