At risk of sounding like your Father the day you got your first set of car keys:
“This is a machine. Machines need oil. CHANGE YOUR OIL!”
Here’s what happens, your filter becomes clogged with contaminants overtime as your oil breaks down. Regular oil changes can significantly increase the life of your automobile’s engine. On top of the oil losing viscosity, over time it can collect tiny metal shavings that eventually either clog up the oil filter or continue to circulate through the engine, marring cylinder walls and other components. Old, contaminated oil may also plug up the screen on the oil pump, reducing its integrity. Now, the actual miles and or months that you need to have your oil and filter changed in your new or used car will solely depend on not only the manufacturers suggestions, but all in your own driving habits. Consult your service technician for the actual miles if you have misplaced your owner’s manual.
If i were a betting man, I’d bet it’s been a while since you’ve changed your oil. In the words of dear old Dad, “CHANGE YOUR OIL!”