I HAVE OIL LEAK AND CANNOT LOCATE THE SOURCE OF LEAK. IT LEAKS WHILE DRIVING AND DROPS ON EXHAUST AND ALL OVER THE TRANS PAN WHERE IS THE OIL SENDING UNIT LOCATED ON THIS VEHICLE

It can be difficult to determine the source of an oil leak, especially if the valve cover has already been replaced. Here are some common causes of oil leaks in vehicles:

1. Engine gasket leaks: Engine gaskets can leak oil, causing oil to seep out onto the engine and surrounding components.
2. Engine oil seals: Engine oil seals can become worn or damaged, causing oil to leak from the engine.
3. Engine oil cooler: Engine oil coolers can develop leaks, causing oil to leak out of the engine and onto the manifold.
4. Engine oil pan: Engine oil pans can develop leaks, causing oil to leak out of the engine and onto the ground.
5. Engine oil filter: Engine oil filters can develop leaks, causing oil to leak out of the engine and onto the manifold.

If you are unable to locate the source of the oil leak, it is recommended to have a professional mechanic inspect the vehicle

well that is its A#1 job to do just that every cool down cycle even on a brand new car.
not told you how long it takes the fluid to drop 1 day ,1 year? or?
but if the engine eat the coolant AF. then the RAD leak down test finds that. (a tool)
most cars we se the Reservoir to 1/2 full.
and goes higher hot engine and back to 1.2full cold
if engine fails (or any leaks of any kind any where)
the level drops, telling any tech or owner there is a very serious problem.
the tool
https://search.brave.com/images?q=radiator+leak+down+tester&source=web

what a tech does if lots spare time
is open hood get engine fully hot 1/2hr driving . (15psi)
and look for leaks. here is short list (ASE basics all)
new cap is best for $5 and holds 15psi and no longer leaks (cap)

1. AF to ground leaks, seen. (AntiFreeze 50%)
2. hoses all leaking AF.
3. leaks to passengers toes ,heater core leaks.
4. leaks from intake manifolds for sure V6 or V8 engines
5. core leaks block or heads. (aka freeze plugs)
6. the tail pipe has steam all the time running (cloud)
7. the head gasket viewed at sides, leaks.AF
8. RAD leaks (all of it) even squirts to places not leaking oops.
9. water pump leaks.
10. engine oil pan shows oil , is milk chocolate. oops super bad.
11. A/T TRANS SAME , HAS AF MIXED IN TO ATF FLUID. RAD COOLER BAD .
12. THOSE ARE SIGNS. OR USE THE PRESSURE TEST TOOL.

best see the leak,as old signs of leaks can lie you, yes leaks but was a squirted to leak ,not THE leak. source.
watch leaks live hood up, and win.
best is not drive this car too far. (circle the block test to get 180f coolant temp?) and cause full pressure to find leaks for free.

There are several possible sources for an oil leak in a vehicle. Some common sources of oil leaks include:
Oil pan gasket: The oil pan gasket seals the oil pan to the engine block. If the gasket becomes worn or damaged, it can allow oil to leak out.
Valve cover gasket: The valve cover gasket seals the top of the engine and helps prevent oil from leaking out. If the gasket becomes worn or damaged, it can allow oil to leak out.
Oil filter adapter: The oil filter adapter connects the oil filter to the engine block. If the adapter gasket becomes worn or damaged, it can allow oil to leak out.
Oil cooler lines: If your vehicle has an oil cooler, the oil cooler lines can develop leaks over time.
Engine oil cooler hose: The engine oil cooler hose connects the oil cooler to the engine. If the hose becomes damaged or develops a leak, it can allow oil to escape.
To determine the source of the oil leak, it will be necessary to visually inspect the engine and related components. It may also be helpful to use a dye or UV light to help identify the source of the leak. If you are unable to locate the source of the leak or are not comfortable attempting to fix it yourself, it is recommended to have the vehicle inspected by a professional mechanic.

FOR oil leak issue check the following help links:---

Common Causes of Car Oil Leaks?

http://schematicsdiagram.blogspot.com/2011/12/common-causes-of-car-oil-leaks.html

--------

Troubleshoot Car Oil leak?

http://schematicsdiagram.blogspot.com/2011/12/troubleshoot-car-oil-leak.html
---------

Car oil leak?

http://schematicsdiagram.blogspot.com/2011/12/car-oil-leak.html

---------
Car oil leaks from valve cover gasket?

http://schematicsdiagram.blogspot.com/2011/12/car-oil-leaks-from-valve-cover-gasket.html

---------
Rear oil seal leaking?

http://schematicsdiagram.blogspot.com/2011/12/rear-oil-seal-leaking.html

------------

leaking oil from oil pan?
http://howtobyme.blogspot.com/2011/11/kia-sportage-leaking-oil-from-oil-pan.html

-------
leaking oil from timing cover?

http://technoanswers.blogspot.in/2012/02/toyota-corolla-leaking-oil-from-timing.html

----------

How to Check Differential Oil Leaks and Replace Oil
http://schematicsdiagram.blogspot.com/2011/07/how-to-check-differential-oil-leaks-and.html

----------
Oil leaks from air filter on ford?

http://technoanswers.blogspot.com/2012/01/oil-leaks-from-air-filter-on-ford.html

-------------
---------This will help. Thanks.

Most likely a head gasket. The coolant is forced into the oil chambers and mixes. This too leaks into the exhaust gases and burns off as you describe. You usually get oil in the coolant reservoir. This can be checked with a test strip available at automotive supply store. It measures the acidity in the coolant.

first is to check the oil pressure switch (near the oil filter)(cheap) if its not that the oil pan and the bottom half of the block can leak (famous Northstar leaks) (BIG $$$)

SMOKE UNDER HOOD COULD BE COOLANT LEAK FROM RADIATOR ITSELF OR CHECK FOR LEAKING TOP RADIATOR HOSE AND CHECK FOR LEAKING BOTTOM RADIATOR HOSE.LOOK UNDER THE HOOD IF COOLANT BOILING OUT COOLANT OVERFLOW JUG ENGINE OVERHEATING FROM BAD THERMOSTAT OR BAD WATER PUMP.CHECK FOR COOLANT LEAK AT WATER PUMP WEEP HOLE.IF SO WATER PUMP NEED REPLACING.ADD MORE COOLANT UNTIL LEVEL CORRECT.TRY LOCATE LEAK. IF CAR OVERHEATED AND BOILED IT OUT. SMOKE UNDER THE HOOD CAN ALSO BE CAUSED BY LEAKING VALVE COVERS WHICH CAN BE FIRE HAZARD IF OIL LEAKS ON HOT EXHAUST MANIFOLD.

is the leak visually on the ground, then it seems like you could get under car and wipe a few things and see what leaks, thats a big leak, car would be leaving a smoke screen behind you from getting all over exhaust system. I would have to say, REAR MAIN SEAL BETWEEN MOTOR AND TRANS, OIL FILTER NOT TIGHT, Is oil all over the timing belt? front gasket/seal failure, Oil sending unit, is the light on or pressure gauge work?

Common area for oil leaks would be from the oil filter, oil line to the cooler attached to the radiator and the other place that is most common would be a faulty oil pressure sending unit.
When the oil pressure sending unit goes bad, oil will leak from the unit. It's made of a metal fitting and plastic top and the plastic will tend to crack after a few long years from the heat making them brittle.
Inspect your oil pressure sending unit and replace if any sign of oil, You can pick up the unit at Auto Zone and can give you the step by step instructions to get the job done with common tools. They would also be glad to help you find where the leak is coming from free of charge.
Thank you for using fixya and if it's your transmission that is leaking, don't drive it if the level is low and take note transmission fluid is flammable and will catch fire from the heat of the exhaust.

Check temp control sending unit and thermostat.