Looking for oil pump location - 1999 Jeep Cherokee

Inside the oil pan,before buying a new oil pump make sure the oil doesn't have glitter in it...if it does,start looking for a new car

if you mean engine oil pump its located at bottom of engine and is driven by the externel drive belt for the pas etc looks an easy job to replace if thats what you are doing have a look on u-tube probably have a video of the procedure

year, make, model, engine size?

How does it run?

Do you see a lot of black smoke out the tailpipe when you accelerate?

do you see anything leaking?

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

the oil pump is located inside the oil pan and has to be removed to get to the oil pump.

SOUND LIKE FRONT CRANKSHAFT TIMING COVER SEAL OR REAR MAIN OIL SEAL LEAKING START ENGINE LET IT IDLE SEE IF YOU SEE OIL DRIPPING UNDERNEATH CAR LOOK FOR OIL LEAK AT TIMING COVER OR AT REAR OF ENGINE WHERE REAR MAIN SEAL LOCATED. CHECK ON TOP OF ENGINE INTAKE MANIFOLD AREA WHERE OIL PUMP DRIVE GEAR IS.O - RING AT THE OIL PUMP DRIVE GEAR WILL CAUSE LARGE OIL LEAK.OIL PUMP DRIVE GEAR IS LOCATED WHERE THE DISTRIBUTOR USE TO BE LOCATED.KEEP EYE ON OIL LEVEL IN CRANK CASE.KEEP PLENTY ENGINE OIL ON HAND UNTIL YOU FIX.I WOULD FIND LOCATE PROBLEM QUICK AS POSSIBLE BECAUSE OIL LEVEL GET TOO LOW ENGINE WILL SEIZE UP LACK OF OIL..

its located inside the engine there is an oil tank type under the engine with about 15 to 20 bolts this is called sump you have to remove it to get to the oil pum But dont try this at home its a technicians job

OIL SENDING UNIT MOST TIME LOCATED CLOSE TO OIL FILTER ON LOWER SIDE OF ENGINE BLOCK.IF OIL PUMP ON FRONT TIMING COVER OF ENGINE LOOK ON FRONT TIMING COVER OR ON THE FRONT SIDES OF THE ENGINE BLOCK.

take off the oil pan, look up. There should be 2 bolts holding the pump, the pump looks like a round screen.

The oil sending unit is located below the power steering pump. 
You can get to it by removing the alternator, then the three bolts around the power steering pump bracket. Remove the small pulley on the bracket and pull back on the power steering bracket. Look behind bracket and you will see the oil sending unit. 

Disconnect the wire from the oil sending unit. Use a deep socket (1 1/16) to remove unit. 

While you have unit remove, I would go ahead and use an oil pressure gauge to test the oil pump pressure. 

Good luck and hope this helps

oil pump in engine is like heart in human body ! do not run engine with out fix it .ck the oil pan,oil screen for mud and tar, oil filter for clogs, the oil pump is located in the L side of engine behand the timing cover next to the water pump