Every combustion engine needs oil, fuel, and coolant to work well. Engine oil keeps the engine’s parts lubricated, preventing early wear and tear. This lubrication is what makes your engine last longer and operate reliably.
Your oil system operates smoothly when your engine has sufficient oil and when your oil pump generates enough pressure to circulate it throughout the engine. If your engine’s oil pressure drops, your vehicle may display various warning signs. These may include the illumination of a low oil pressure light on your dashboard, increased engine noise, or the detection of unpleasant burning odors.
But what do these signs signify? Various issues can lead to a decrease in oil pressure, with some being more urgent than others. Here are the top five causes of low oil pressure and the services and repairs your car requires to address each.
1. Not Enough Oil
One of the simplest and most common causes of low oil pressure is a lack of oil in your engine. If the oil levels are too low, your oil pump cannot generate enough pressure to keep your engine lubricated. The potential consequences are reduced lubrication, increased wear and tear, and a higher risk of engine failure.
Follow these steps to check your oil levels and determine if you need a top-off:
- Ensure your vehicle’s engine is off, then pop the hood open.
- Locate the oil dipstick, typically identifiable by a yellow ring or handle featuring the stamped oil symbol.
- Remove the dipstick and wipe off any oil residue from its surface using a rag. Residual oil can lead to inaccurate dipstick readings.
- Reinsert the dipstick fully, then withdraw it once again.
- Examine the oil level on the dipstick. Each dipstick typically features two indicators: one for full and another for low levels. You can usually identify the low-level indicator by the word “ADD” or a symbol that indicates that you need to add oil. Your car requires a top-off if the oil level is below this indicator.
- Refer to your owner’s manual, and use the brand and type of oil your vehicle manufacturer recommends for your specific model and trim level. Some vehicles may indicate the type of oil required on the dipstick or oil cap (e.g., 5W-20).
-
2. Your Vehicle is Leaking Oil
Did you recently replace or replenish the oil, only to see a low oil pressure alert a few days later? You could be dealing with an oil leak. Although the indications of an oil leak may initially resemble low oil levels, inspecting for signs of leakage is crucial to prevent unnecessary expenses on oil refills.
Oil leaks are among the most common causes of low oil pressure in older vehicles. This is because many of their components, such as oil lines, are more prone to wear, deterioration, or damage. If you suspect your car has developed an oil leak, keep an eye out for these signs:
- Oil spots under your car. Cars with an oil leak typically leave oil puddles on the ground where they were parked. On dry asphalt, oil leaks may appear brown, black, or dark colored. If it recently rained, the water may make the oil appear multicolored instead, giving off a recognizable rainbow pattern on the surface.
- Smoke from the engine bay. When starting your vehicle, check whether smoke is escaping from the engine bay. Depending on the location of your oil leak, it may fall on hot components, such as the exhaust manifold, burning and causing smoke. If smoke isn’t visible, check for odd scents, such as the smell of burning oil.
- High engine temperature. Oil leaks can decrease your engine oil levels to unsafe levels during driving. If you observe a sudden increase in your engine temperature gauge while on the road, it may be attributed to a leak.
If you’ve detected indications of an oil leak, schedule a service appointment with a reputable local auto mechanic. They can identify the leak, repair it, and replenish your car’s oil.
3. Dirty or Clogged Oil Filter
Every combustion engine has an oil filter designed to capture and eliminate impurities from the circulating oil as it moves through the engine and oil lines. Over time, these filters deteriorate and become congested with accumulated grime and debris, a process accelerated in dusty environments or when using old, degraded oil.
As grime and impurities build up within your oil filter, its effectiveness diminishes. This can restrict the flow of oil and lead to a drop in oil pressure. If your oil levels are satisfactory and there are no signs of oil leakage, it’s advisable to schedule an oil filter replacement soon.
A general guideline for modern vehicles is to replace the oil filter with every oil change. With more durable oil formulations, modern cars often exceed 6,000 miles between oil changes. Consequently, filters must maintain efficiency over longer periods.
While you can continue driving with a dirty oil filter, you shouldn’t wait too long. Modern oil filters have a bypass valve that engages when the filter is excessively clogged, allowing oil to bypass filtration to prevent engine oil starvation. However, once activated, the bypass valve permits unfiltered oil into the engine, posing a risk of accelerated engine damage or wear.
4. Bad Oil Sensors
If you keep getting low oil pressure warnings even after changing the oil and replacing the filter, the issue might be faulty oil sensors.
Your car’s computer relies on these sensors to monitor current oil pressure levels and decide when to display a low oil pressure warning on the dashboard. If the sensors malfunction or fail, they could send incorrect readings to the computer, mistakenly indicating a low oil pressure problem.
It’s best to schedule a service appointment with a mechanic to fix this. They can inspect your car’s electronic system and determine whether the sensors need replacing.
5. Worn Out Oil Pump
Oil pumps can degrade over time due to general wear and tear. This can lead to a decrease in oil pressure as their internal components become less efficient.
If your dashboard displays low oil pressure warnings even after an oil change or filter replacement, the oil pump may be at fault. A skilled mechanic can identify this possibility while examining your car’s oil sensors. If the sensors are not faulty and there is no other evident cause for the low oil pressure, a new oil pump might be necessary.
Your mechanic can assess the condition of your oil pump and determine whether it can be repaired or requires replacement. They can handle the necessary services, ensuring that your vehicle’s oil system operates normally once again.