Engine problem ok what happen is the oil presser gauge was bousing up and down and my roomates and i really did not know what was happening and we kept driving well when i was at a friends house i was called and told the the engine was making a clancing sound and it was not till later that i found out that it ran out of oil and now it sits and i am not sure if we should just put oil in it will it be ok or will we have to get a new engine

the oil pressure sensor tells the ECM when there is insufficient oil pressure to safely run the engine
when you start an engine there is oil covering the pump inlet and the pressure buils up
if there is insufficient oil to maintain pressure ,or the pump cannot maintain a low preset pressure , the ecm will shut the engine down to protect it
like wise if the wiring is loose /faulty the signal from the sensor is interrupted and that tells the ecm to shut the engine down
again if the sensor is faulty , the ecm will shut the engine down
how to fix :-
install a mechanical oil gauge in the system and check for oil pressure achieved
replace the sensor switch with a known good one
run the fault codes

If the gauge is showing zero pressure, you would next check the pressure with a mechanical gauge to verify.
Make sure you use a tee fitting to keep the electric sensor in use while testing.
If the pressure really is zero, something has happened to the oil pump in the oil pan.

I have an oil pressure gauge that reads in analog, 0 to 150? something like that, any way, it moves like a tachometer, idle down around 10, revs up to 55, 60 when taking off and then settles down at 35 while cruising, I notice a change with heavier oil. Also, I know it will read 55 lbs pressure with 1 qt of oil in there, I tried it. So the pressure gauge has nothing to do with amount of oil in engine. As long as it is full, It should be ok, as long as it is reading pressure, but if the pressure drops off, shut it down and find out what happened, If it loses all the oil, the temp light should come on long before the oil light.

One of two things may be happening. If the oil light stays off until the engine warms up and then begins to flicker on/off when you are idling & in gear [say at a stop sign] then you could actually have low oil pressure due to worn internal engine parts, OR, you could have a faulty sending unit that is reading the pressure incorrectly [usually low] and turning on the light. The best way to find out for sure is to have someone remove the sender and thread in an oil pressure test gauge to check and see exactly how much oil pressure you really have when the engine is first started and fully warmed up. You could just simply replace the sender and if the flickering is gone after that then you should be ok but if the flickering continues then odds are you actually do have low oil pressure. I would strongly recommend having the oil pressure tested for peace of mind then you'll know for certain what is happening. Engine bearings don't survive very long without sufficient oil pressure so you should have it checked out asap.

In order to be sure u don't have a low oil pressure condition it is very important that u have a shop hook up a test gauge to the engine and verify the actual oil pressure, if that pressure is ok then they can replace the oil pressure sending unit and that should correct the light problem. Remember if the pressure is really low you run the risk of serious engine damage and a $3000.00-$4000.00 bill for a new engine.

Mate .2 things.The oil pressure sending unit is playing up or its not.The other is how long since an oil /filter change.If you know the oil is ok ,get the sender unit fixed.Oil is a lot cheaper than metal if things are not right.If it happens all of a sudden,the sender unit may be at fault.Hope this helps

There are two basic causes. One, that your oil pressure is really too low at idle. You did not state the mileage, but if the vehicle is high-mileage, this is a possibility. The other is the oil pressure sender is bad, and reporting low pressure when it is actually OK. The best way to know for sure is to have a shop test the actual oil pressure using a calibrated gauge. If the vehicle is lower mileage, and you think the pressure is really OK, it may be cheaper for you to just replace the sender as a test(if you are mechanically inclined enough to do it yourself). If the warning light goes out, the old sender was bad.

If replacing the sender does not cure the problem, then you have low oil pressure. This will shorten the life of the engine, so you need to have a mechanic diagnose the problem. Possible causes are: bad oil pump, excessive bearing clearances due to high mileage, oil pump intake blockage due to sludge in the oil pan, stuck pressure relief valve. Unfortunately, none of these problems will be cheap to fix.

This is OK. Oil pressure is always higher when the engine is cold.

As an engine accumulates miles the pressure will start to drop due to bearing clearances increasing.

If this just started to happen you may want to replace the oil filter and or oil pressure sending unit.

The oil pressure should go down after the engine heats up because of its viscosity. When you accelerate the pressure should go up and at idlen the pressure goes down. 20-40 psi range is normal.

Any where from a quarter to half way is fine. After this the oil presser is getting to high. be sure you run 10-30 in the winter and do a oil change in spring time to 10-40 . oil will thin in hot temp. thus using a thicker oil like 10-40 in the summer will help keep oil presser down .