If you’re running your engine without the right amount of engine oil, your engine will incur severe damage. Many systems in your vehicle are designed to monitor the motor oil pressure and level.
For the car computer to oversee motor oil pressure, the oil switch needs to be in good working order. The oil switch, also known as the oil pressure sensor, works together in harmony with the oil pressure gauge in your instrument cluster.
When the sensor detects low oil pressure or low oil level, it will send a signal to the car computer, which will, in return, ask the pressure gauge to reflect the change. And that will trigger the oil warning light to pop up on your dashboard.
Failing to recognize low oil pressure symptoms and symptoms of high oil pressure and fix them on time can lead to catastrophic engine damage.
What Does Low Oil Pressure Mean?
Motor oil is essential for proper engine operation. The oil lubricates (provides a liquid barrier between) internal engine components, reduces friction, and helps keep the engine cool.
There must be sufficient oil pressure so that the oil can circulate throughout the engine and reach the necessary internal components.
The oil pump, which is driven off of the engine’s camshaft, crankshaft, or distributor, pulls oil from the oil pan whenever the engine is running.
From there, the pump forces the oil into the engine’s lubrication system. Oil pressure is created by the resistance the oil encounters while circulating through the engine.
Low oil pressure is just what it sounds like—a lack of oil pressure inside the engine. There are several reasons why an engine might be suffering from low oil pressure, as we’ll discuss below.
Why is Oil Pressure Important?
Oil pressure is essential to the proper functioning of an engine because it ensures that engine oil covers all moving parts. Having the right oil doesn’t matter much if it can’t cover the parts it’s meant to protect.
Oil pressure helps oil flow throughout your engine, covering key components and protecting them from heat, friction, and vibrations. Oil pressure facilitates oil flow, ensuring optimal functionality.
If oil pressure drops below base operating levels, your engine oil will stop flowing. This means your engine oil will be unable to protect your engine because it cannot coat your key components.
Low engine oil pressure could mean your engine is running like it didn’t have engine oil.
Low oil pressure symptoms
The main symptoms of low oil pressure include:
- Oil pressure light on dashboard
- Bad noises from engine
- Check engine light
- Seized Engine
Here is a more detailed list of the signs of low oil pressure to look for:
#1. Oil pressure light on dashboard.
The first thing you will notice if your car has low oil pressure is the warning light on your dashboard.
The oil pressure sensor is monitoring the oil pressure all the time when the engine is running. If the oil pressure gets too low or too high, it will light up the oil pressure light.
Remember that a faulty oil pressure sensor can give false signals to the dashboard.
#2. Bad Noises from engine.
The other widespread symptoms of low oil pressure are rattling and other strange noises from the engine. The oil pressure prevents engine parts in the engine from rubbing metal against metal, and if the oil pressure is low, they will start rubbing against each other.
This can create a horrible sound, and if you hear this, you should turn off your engine immediately.
#3. Check engine light.
The oil pressure also controls tensioners like the timing belt or timing chain tensioner. It can also control different pumps like the fuel pump if you have a diesel engine.
For example, if the oil pressure is low and the chain tensioner won’t tension the timing chain, the camshaft timing will be off, and the check engine light will turn on.
#4. Seized Engine.
This is the last and the worst symptom. You never want this to happen. If you drove your car with rattling noises and an oil pressure light on your dashboard until it stopped working, your engine has probably seized.
A car engine that has seized after running on too low oil pressure is often not possible to repair. It is unfortunately often cheaper to replace the whole engine.
Low oil pressure causes
The oil pressure in an engine can be low for a number of reasons. When the pressure gauge detects low oil pressure, be aware that it may be real or just an inaccurate reading. In any case, it helps to understand some of the most common causes.
#1. Not Enough Oil in the Engine.
Even if the correct amount of lubricant has been added during an oil change, the oil may be unduly consumed due to evaporation, burning caused by worn piston rings, and leaks through the seals or oil plug.
Oil consumption increases as the engine ages, so checking the oil level and topping up may be a simple solution. However, if leaks are evident outside the engine or there are oil drops on the floor, the leaking component should be fixed as soon as possible.
When an engine is old, it will burn more oil. When the engine consumes a quart of oil every 1,000-2,000 miles, an overhaul is needed.
If the oil change interval is overextended, the oil level could be quite low, even if the engine is not very old. Therefore, follow proper oil change intervals and check the oil level periodically.
#2. Too High or Low Viscosity.
When oil viscosity is too low or high, it may be detected as a loss of pressure in the oil supply to the engine. Low viscosity generates less resistance to flow through the system, which is translated as lower pressure by the pressure gauge or sensor.
Viscosity that is too high may produce greater resistance from the oil being pumped, leading to a lack of lubrication in the system and consequently lower pressure.
In an engine, oil viscosity is influenced by the original lubricant viscosity selected, the operating temperatures, the breakdown of viscosity index improver additives and the presence of contaminants such as glycol and soot.
The engine or car manual should specify the recommended viscosity grades according to the equipment’s design and the ambient temperatures where the vehicle will be operating.
A higher viscosity selection may be a concern, particularly for engine startups in cold weather. In extreme low temperatures, not only must you choose the right lubricant viscosity, but you may also need to use an oil heating system.
Low viscosity can be the result of a variety of factors, such as fuel dilution, incorrect lubricant viscosity selection, or excessive temperatures due to overloading or a cooling system failure.
#3. Apparent Low Pressure.
In diesel engines, the pressure gauge typically reports real-time pressure in pounds per square inch or bars. Some lubricant manufacturers produce lubricants with a lower viscosity that is still within the range of the SAE grade.
A lower viscosity offers better fluidity through lubrication systems but may result in lower pressure in the pressure gauge. If the pressure is within the normal range, there is no cause for concern. You may find that some lubricants produce higher pressures than others.
#4. Engine Wear.
If the oil level on the dipstick is between “add” and “full,” a possible cause of low pressure would be worn engine bearings, especially if the engine has very high mileage.
Excessive wear reduces the original flow restriction, which consequently drops the pressure. If this is the case, the engine likely will need to be rebuilt or replaced.
#5. Defective Oil Pressure Gauge.
If the oil pressure warning light has come on but you have confirmed that the oil level is correct and the engine is running normally with no unusual noises or high temperatures, the problem may be a defective sensing unit.
You may wish to have the oil pressure tested with a gauge. If the pressure is normal, simply replace the oil pressure sensor. However, if the warning light or low gauge reading continues after replacing the sensor, the problem is likely a bad oil pump.
#6. Pump Wear.
If the oil level on the dipstick is between “add” and “full” but the engine is running noisily, the oil pump may be worn.
A worn pump is unable to generate the necessary pressure due to internal leaks. Stop the engine until the issue can be fixed. A pump replacement will be needed.
#7. Plugged Filter.
In a lubrication system, the pressure gauge is installed after the filter. If the filter becomes clogged with contaminants and the bypass valve does not operate correctly, it may lead to lubricant starvation.
A clogged filter is often the result of an overextended oil. It may also be caused by water and/or soot contamination.
Water typically comes from a cooling system leak, while excessive soot may be the result of poor combustion. If the bypass valve is not working properly, a defective filter may be to blame.
Above is a flow chart detailing the inspections and corresponding actions for low oil pressure in an engine.
How Do You Diagnose Low Oil Pressure?
- Check the Oil Level: The first step is to check if there’s enough oil in the engine. This can be done using the dipstick.
- Check the Oil Pressure Sensor: The sensor could be faulty and give an inaccurate reading. You can use an oil pressure gauge to verify.
- Inspect the Oil Filter: A clogged oil filter can cause low oil pressure. If the filter is dirty, consider replacing it.
- Examine the Oil Pump: A failing oil pump can lead to low oil pressure. Listen for any unusual noises that might indicate a problem.
- Assess the Engine Oil Viscosity: Use the correct oil viscosity as recommended by your vehicle’s manufacturer. Too thick or too thin oil can cause low oil pressure.
- Look for Oil Leaks: Check for any visible signs of oil leaks in your engine.
- Check the Oil Pressure Relief Valve: If the valve is stuck open, this can cause low oil pressure. It may need cleaning or replacing.
- Inspect Internal Engine Components: Worn-out bearings or other internal engine parts can cause low oil pressure. This usually needs professional assessment.
How to fix low oil pressure?
When your oil pressure light comes on, it means your computer says your oil pressure is low. In the next few paragraphs, I will show you how to diagnose and carry out a low oil pressure fix.
Things Needed
- Underhold work light
- Socket set
- Wrench set
- Screwdrivers
- Cleaners
- Oil catch pan
- Safety glasses and
- Protective gloves
Step 1: Park your vehicle.
Park your car on a level and hard ground. Put on the hand brake.
Step 2: Check the oil level.
Next, shut off the engine and open the hood. Pull out the dipstick and see if your low level is oil. Remove the dipstick, wipe it off, push it back in, and then pull it out and check the oil level.
If your oil level is low and you’re close to the scheduled oil change date, you have to service your engine, test drive it, and see if the light will disappear.
But if you just did a recent oil change, you might want to top up the oil. If the engine oil is gauged, you have to move on to the next step. Pretty dirty oil can cause trigger oil light.
Step 3: Check if your oil filter is pumping.
While the engine is off, slack the oil filter, but don’t take it off completely. Then have an assistant start the engine while you see if engine oil will throw out with pressure. If it doesn’t, that means you have a faulty oil pump that needs replacement.
However, if the engine was giving a knocking sound and stopped when you slack the oil filter, chances are you have a clogged oil filter. Your best bet is to purchase a quality oil filter and replace the clogged one.
Step 4: Check the oil switch.
The oil switch communicates with the car computer about engine oil pressure. The spring inside the switch can wear out and send false readings to the car computer.
Since you cannot check the sensor yourself, it’s a good idea to buy one and replace it. It is inexpensive and will cost only a few bucks.
To replace the oil switch, you have to locate it first. It is usually found near the oil filter. Once you locate it, you can slide it under your vehicle and replace it using the right socket set and ratchet.
In case the oil filter is blocking your path, remove it so you can gain balance and install the new oil switch.
Before installing it, get some thread tape and tape the oil switch thread. This will prevent it from leaking anytime soon. And, of course, remember to reinstall the oil filter.
Step 5: Clean your oil strainer.
One of the common causes of low oil pressure is a clogged oil strainer. It is found in the crankcase and attached to the oil pump. If you have checked the above steps and everything seems okay, chances are you have a clogged oil strainer.
To clean the oil strainer, you might have to drain out the engine oil and lose the crankcase. Pry it out and locate the oil strainer. If it’s clogged, unbolt the bolts holding it and clean it with fuel.
Apply sealant on the crankcase and reinstall it using the reserve process. If you notice the low oil causes rough idle and you see engine sludge in the crankcase, you would want to add an engine restore additive to your engine.
FAQs.
Q: Can you drive a car with low oil pressure?
No, driving a car with low oil pressure or low oil level can severely damage your engine system.
If low oil light pops up on your dashboard while the vehicle is running on idle or driving, you have to park, turn off your engine and have the issues addressed before hitting the road.
Q: How long can an engine run without oil before damage?
Engine oil plays a significant role in the smooth running of an engine. Arguably, an engine will run without oil in it. The engine can run 5-10 minutes before failing. And in most cases, it can fail a lot quicker.
Q: Can low oil damage the engine?
A low oil level in an automotive engine is likened to someone with deficient blood in the system. Extreme low engine oil can cause catastrophic damages that may require rebuilding or replacing the entire engine.
Q: What does a car sound like when it needs oil?
If you ignore the signs of low oil pressure for a long, the engine will start making a rumbling, Knocking, or even roaring to let you know that it needs oil. Prior to this point, the engine must have incurred severe damages.
Q: Will the check engine light come on for low oil pressure?
The check engine light usually comes on when there are issues in the engine. If you have low oil pressure, it will affect other engine components and, thus, cause the engine warning light to come on.
Final word
Visiting a mechanic garage for scheduled maintenance is crucial to preventing unnecessary repairs in your vehicle. You should regularly monitor your engine oil level and pressure, and it doesn’t take much effort and time.
Not watching out for low oil pressure symptoms, knowing the causes, and fixing it on time will cause tremendous engine damage that may require rebuilding or replacing the entire engine.
Hence, ensure you fix low oil pressure at the earlier stage or call for professional assistance.