There really is no more important issue related to the performance and longevity of your car’s engine than the oil inside your vehicle. Motor oil (also called engine oil ) is pumped throughout the inside of your engine in order to coat all of the moving metal parts with a thin layer of lubrication to keep them from rubbing against one another. But if the oil pump fails, or there is some other reason that the oil pressure drops, motor oil will cease to make its way to where it is needed.
It does not take very long for an engine to fail without adequate lubrication. Fortunately, your car is smart enough to tell you not only when the oil level is low, or when it is time for an oil change , but also if and when the oil pressure falls below its proper range. Some of the signs of low oil pressure are built in as a safeguard; other telltale symptoms are unintended but happen nevertheless. Here are the results of low oil pressure, the signs that your oil pressure is low, and the causes that can create the condition.
Results of low oil pressure
What happens when oil pressure is low? Well, for one, when the oil pressure drops, oil is unable to reach all of the moving components inside the engine. There are literally hundreds of them, from the pistons, bearings, valves, camshafts, and more. Far more. If any component loses its lubrication, it will make metal-to-metal contact with other components. Degradation happens almost instantly. Your engine cannot run without motor oil.
One sign of low oil pressure can be a decline in engine performance – a loss of power, reduced fuel economy, and stalling. Of course, decreased engine performance can be attributed to several problems besides oil pressure, and by the time an engine is seriously underperforming and stalling out due to low oil pressure, most likely a good deal of damage has already occurred.
In fact, if your engine loses oil pressure, it will not run for long. How long will an engine run without oil pressure? Maybe – and that is a big maybe – a half hour. Most likely less. Then it is time for a new engine, after you have solved the issue of being stranded wherever your engine decided to give up the ghost.
Signs of low oil pressure
There are a few reasons that the oil pressure could drop in your engine. If it does, your car has a built-in warning system to let you know. If it fails to do so, or if you ignore the initial signs, your engine itself will eventually tell you something is wrong. Catching the problem early on is a key to long engine life. Besides a general decline in engine performance, here are some other symptoms of low oil pressure:
- The oil light illuminates on your dashboard display. The oil pressure warning light is in place to do precisely what it suggests: warn a driver that the oil pressure is low. Just like your brake system warning light , the oil light is not a mere suggestion that there could be a problem. It is a warning – that something is wrong! The warning could also be reinforced with a message on the vehicle’s digital display. Whether or not that is true, when the oil pressure warning light comes on, it is essential that you seek service immediately or otherwise stop driving.
- Engine noise. If you begin to hear strange sounds coming from your engine , it could mean that the oil pressure is low. A lack of oil causes wear to the internal parts of your engine. Let your oil pressure drop and you might hear the valves rapidly clicking, ticking, or clacking. Let it remain low and other components, like the piston rods and the crankshaft, might start knocking. If you hear any of these sounds coming from your engine, stop driving! Depending on how much damage has been done, you might yet be able to save it. Keep driving and all bets are off.
- Burning oil smell. One reason that your oil pressure could drop, as you will see below, is if your engine runs low on oil. When the oil level drops, there is less oil for the oil pump to circulate through the engine. Less oil, less pressure. Low oil can happen for multiple reasons, one of those being an external engine leak. If your oil is leaking onto a hot surface, like the exhaust system, you might smell it burning. Your oil also breaks down faster when the level is low, and that can lead to a burnt odor as well.
- Engine overheating. Your engine is designed to operate within a designated temperature range, somewhere between 190 and 220 degrees Fahrenheit. There are several reasons that an engine would overheat – faulty thermostat, low coolant level, and (you guessed it) low oil level and pressure. Motor oil plays a role in heat management within your engine. Not enough oil and your engine will get hotter than it should.
Causes of low oil pressure
If you notice any of the issues above, stop driving your vehicle. Have it inspected by a qualified technician at a trusted repair shop so that you can avoid costly repair bills. If these signs or symptoms do show up, the cause is likely one of the items below (in no particular order).
- Improper oil viscosity. Motor oil viscosity (also referred to as the weight or grade ) refers to the thickness of the oil, its resistance to flow. You might be familiar with terms like 5W-20 or 0W-16; those codes are related to the viscosity of an oil product. If the viscosity of the oil does not match what the manufacturer recommends for your engine, it could cause low oil pressure. The type and weight of oil you use in your engine should always match what the manufacturer recommends in your vehicle owner’s manual.
- Bad oil pressure sensor or oil pump. If the oil pump is not working properly, your engine will not see sufficient oil pressure. Likewise, if the oil pressure sensor is faulty, you could get a false pressure reading. In either case, you should see the oil pressure light come on (or the pressure gauge show a low reading), so have your vehicle serviced to correct the condition.
- External or internal oil leak. Over time, your engine becomes susceptible to oil leaks and other fluid leaks. Whether and how soon an oil leak develops may depend on how consistently you change the oil and the quality of the oil you use. As already discussed, an overheated engine can be a cause of low oil pressure, but it can also lead to an oil leak. And leaking oil can cause low oil pressure.
- Dirty oil filter. There are several car filters that need attention periodically. The oil filter on your engine is in place to clean out any particulates in your oil, such as dirt that makes its way into the engine or debris from engine component wear. Oil filters should be replaced with every oil change service. Otherwise, if they get clogged, oil pressure will drop.
Low oil pressure is no joke. Keep driving when the pressure drops and you will seriously damage your engine. If your oil light comes on or you see any other signs of low oil pressure, have your engine serviced as soon as possible.