Oil tempature gauge fluctuates sporadically

The oil temperature sensor could be in the oil level sender unit - it depends how many connecting wires there are. If it is in there it would not be as accurate as if it is placed in the main oil gallery, perhaps combined with the oil pressure sensor.

I advise you to re-read your vehicle handbook and ensure you know the exact functions of the instruments. Often the oil gauge is a level gauge only until the engine is started and then becomes an oil pressure gauge, therefore a fluctuating gauge might indicate a fluctuating oil pressure...

If that is so, worrying about it now could save worrying more expensively later.

check the oil level in the sump to ensure that oil was added after draining it for the change
There is a oil pressure sensor / oil level gauge ( different to the oil pressure gauge sender unit) that will not allow the engine to start if there is no oil pressure sensed or no oil level sensed
check for wiring connections as well

Watch the temp gauge when the electric radiator fans come on. The temp sensor that controls when the fan comes on may be faulty.

no,,, fluctuations mean =low oil pressure,oil level low,oil old or too thin viscotly,oil pump loosing or not develloping the correct pressure
pressure release valve spring weakened

If the oil pressure is good and there is no engine noises then the oil pressure sending unit is the problem.Just replace it and you should be good.Hope this helps.Good luck.

oil pump might be going bad

I would assume that it would be your water pump. Check to see if the fluid is comming off of the water pump in the front of your motor, you should be abe to see a drip on the botom of the pully.

replace the sensor, it is the most common issue.

The oil pressure sending unit is a sensor with an internal diaphragm, if the internal diaphragm is damaged , or the line to the diaphragm is blocked you can get this kind of fluctuation on the oil pressure gauge.

The oil pressure value must be read by installing a mechanical gauge near to the oil pressure switch and checking the pressure.

If pressure is ok, replace the sending unit. If there is a real pressure drop, check the oil pump.

If you still get fluctualtion after replacing the oil pressure sending unit, replace the oil pressure gauge.

I wouldn't worry about it unless you see this happening regularly over a period of time. If you got a bad batch of gas, or something along those lines, it could've caused it to happen. If it hasn't happened again, and you have no check-engine light and your fuel economy is where it usually is, I'd chalk it up to a random occurrence and not worry about it. If it starts happening more, try and note as many things as you can about the situation (ie, how long it sat, how much gas in the tank, is the engine warm or cold at startup, any recent maintenance or repairs, etc) - all of that can help a diagnosis.