Jumpy oil gauge 2000 Jeep Grand Cherokee

To verify there is a problem, remove the oil pressure sending unit, replace it with a test gauge, start the car, idle, accelerate etc and watch the gauge for any abnormal variations it should react to evry change in acceleration and not be below the minimum or above the max as per the service specs.

whistling noise is prob. intake leak or emmissions air flow problem, the oil gauge, is either , oilpump screen clogged, or gauge prob. or if a lot of miles it could be the engine is just getting weak, or oil pump itself. check oil level, and sensor for leaks .

First thing you should do is put a mechanical gauge (the factory one in the vehicle is electro-mechanical) on the engine for testing. If it reads the same as the one in the vehicle you either have a blocked pump pickup in the pan or one or more crank bearings are worn out of clearance.
If the mechanical gauge reads normal pressure, replace the sending unit. If you don't have a mechanical gauge available you could replace the sending unit and if it does not help, then you can assume either a blockage or wear is the cause.

First check the oil level and top up as necessary. If the oil pressure is at 0 , then it would very quickly sieze the engine, that not being the case, it sounds like you need to replace the oil pressure switch/sensor, which will be mounted either on the engine block or on the oil filter housing. Hope this helps

this is normal

You'll need to determine if the oil pressure is actually changing, or if the sending unit or gauge is lying to you. Be certain the oil level is up to normal, then check the actual oil pressure with a test gauge. If the pressure varies (drops) at engine idle, perhaps your pressure bypass is defective, or perhaps the oil pump is worn. Testing with a known good pressure gauge should lead you in the right direction.

Last week my 2001 Grand Cherokee with a 4.7 was dropping below 10 and my "check gauges" light and chime came on. My sending unit was bad. I could see it was bad because oil was getting through the unit and leaking very slow. It's located above the oil filter. Easy fix, but the unit was over $50 and the 1 1/16 special deep socket for sending units was over $10.

it could be the sensor you should look at the oil pressure relief valve

have a 2000 jeep grand cherokee with 84,000 miles. started having issues with oil pressure gauge going crazy up and down, beeping. had oil pump replaced per mechanics recommendation. didn't help won't hold pressure---only registers about 2. now they tell me i need a new motor!!! just bought vehicle less than 1 yr ago...had carfax clean report!!!!any suggestions?

sounds to me like you have a bad oil pressure sinding unit