5 Common Causes of Low Oil Pressure

5 Common Causes of Low Oil Pressure

31st Jul 2018

engine oil pressure

Causes of Low Oil Pressure

Have you noticed the oil light illuminated on your car's dashboard? If so, your car may have low oil pressure. For oil to effectively reach all the areas of the engine where it's needed, it must be pressurized. Low pressure results in oil sitting at the bottom of the pan rather than being pumped into the engine. Here are five common causes of low oil pressure.

#1) Failing Oil Pump

One of the most common causes of low oil pressure is a failing oil pump. Just like automotive cooling systems use a water pump to force coolant through the radiator and engine, there's a similar pump used to force oil through the engine. Known as an oil pump, it pumps oil from the bottom of the pan into the engine. If the oil pump fails, however, this won't occur, resulting in low oil pressure.

#2) Bad Rod Bearings

Over time, the rod bearings of an engine may degrade, creating additional clearance while subsequently reducing oil pressure. According to some reports, clearances between the rod bearings and crankshaft of just .001 inches may cause 15% to 20% loss of oil pressure. If this is causing oil pressure in your car, you'll need to replace them to fix the problem.

#3) Wrong Oil

If you recently changed your car's oil, perhaps you used the wrong type. There are synthetic oils, conventional oils and hybrid oils, and different cars are designed for different types of oil. If you used a high-viscosity synthetic oil when the automaker recommends a low-viscosity conventional oil, for example, you may experience low oil pressure. This is because high-viscosity oils don't move as freely through the pan and engine as their low-viscosity counterparts. Always refer to your car's owner manual for more information on what type of oil to use and how much you should add.

#4) Clogged Filter

As the pump pulls oil from the pan, it forces the oil through a filter before sending it to the engine. Here's the thing: If the filter is dirty and clogged with debris -- common in high-mileage vehicles when the oil filter isn't charged regularly -- oil may remain stuck at the pan. And without oil pumping to the engine, you may discover the oil light illuminated on your car's dashboard. Thankfully, replacing the oil filter is a quick and easy job that most people can do themselves.

#5) Oil Leak

Finally, an oil leak can cause low oil pressure in your car. Depending on the specific type of car that you drive, it may hold anywhere from 5 to 8 quarts of oil. You can pull the dipstick to see if it's low on oil. If the dipstick shows below normal oil levels, it may indicate a leak, in which case your car may suffer from low oil pressure. You can pour additional oil into the top of your engine to reach the desired level, but this is only a temporary solution. Ultimately, you need to find and fix the leak. Otherwise, the new oil will leak out as well.

low oil pressure graphic