Running an engine completely out of oil will always end in an expensive disaster. If you’ve found your engine is out of oil and now need to know if your engine is damaged, you’re in the right place.
This article covers how you will tell if the engine is damaged from running with no oil and what to do if you find yourself in this situation.
To be clear, if you suspect the engine is damaged from no oil, you should immediately switch the car off. Even though many of the problems to diagnose the problem indicate car would need to be running, we do not recommend doing this. Without taking the motor apart, it’s impossible to say which components are damaged, and more damage will be done by running the car.
How to tell if engine is damaged from no oil
The most noticeable problem on an engine damaged from running with no oil is the increased and changed engine noises. You will hear the grating noise of scored metal components and damaged bearings being forced to rotate in the bottom of the motor. The noises to listen for are the grating of metal rubbing and knocking noises.
An engine with a loud tapping noise is a sign that the top of the engine may have a problem; valves and springs open and close rapidly; if these become dry, they can break, which you will hear when revving the engine. The noise will be horrible and loud; the car should be switched off immediately.
Regardless of the oil level, if engine components become scored or damaged, you can sense a burning smell. The burning is the friction and scoring getting worse as damaged engine components come into contact with each other. If oil seals have become dry and the engine was topped up with oil, the oil would enter the cylinder, where it would be combusted, and the smell would be apparent.
The oils job is to keep engine temperatures down by keeping moving components lubricated. If there is no oil in an engine the rotating components dry out creating friction. Friction means increasing heat temperatures. Eventually the heat in the engine will rise to levels at which any remaining oil will be burnt away this will cause the engine seize. At which point the engine will be damaged to the point it will probably need replacing. This is all worse case of course.
Overheating will usually be a sign the engine is low on oil at which point topping up may be all that’s required. But a constantly overheating engine with the oil level correct may be a sign of a damaged component from running with low or no oil.
The check engine light or low oil pressure lights illuminated on the dashboard signify the engine may be damaged. If the engine has been run with no oil, the low oil pressure light indicates that damage has been done to something. But it would be impossible to say if it is an internal engine or a supporting component without checking for the low oil pressure specific fault separately.
A damaged engine will not travel through the revs smoothly and will not have the same performance as it did if you were to drive the car, even if you did top the oil level back up. The engine could be hesitant or jerky when trying to drive. In summary, any changes in performance if the motor has been run low or with no oil indicates damage has been done.
What happens to an engine without engine oil?
If you continued to run an engine without oil, it would eventually seize solid. The engine would shut off, the wheels would lock up, and lots of smoke would bellow. If it got to this point, multiple components in that engine would’ve failed in a variety of different ways. Which include:
- Block cracking
- Pistons and rings fusing to the cylinder
- crank wears down
- Bearings score
- Camshaft lobes wear
- Valve springs break
This is just a short list of failures that happen, and not all of them that can.
How long can you run an engine without oil?
An engine can fail in a matter of seconds without oil, but it can also last upwards of 30 minutes. An engine relies on being lubricated to keep friction and heat levels down. So, depending on how much lubrication was left on these components will depend on how long it will last, but there are no guarantees. There are lots of YouTubers who have carried out such tests, which you can see below
What can cause an engine to run out of oil?
The most common and obvious causes of the engine to run out of oil are:
- Oil leak
- Running low on oil
- Using incorrect viscosity oil
Sticking to recommended service schedules, you will likely be using the correct oil, so there shouldn’t be any dangers of the oil burning away. Regularly checking the oil level will ensure you are not running the engine low on oil. It will also highlight any potential oil leaks.
How to fix your engine after running it without oil
Fixing an engine run without oil can be a complicated and expensive process, as the lack of oil can cause significant damage to the engine’s components. It is so rare that you can run a machine for a few minutes, switch it off, top it back up with oil, and the engine will run right after. Although depending on the age of the car and the value of the vehicle against the cost of repair, filling back up with oil and driving until the engine fails can also be an option, but not one we recommend.
Here are some general steps to follow if you suspect your motor has been damaged due to low or no oil:
- Stop driving your car immediately if you suspect your engine has been damaged due to a lack of oil. Running the engine without oil can cause severe damage, and continuing to operate the vehicle can exacerbate the issue.
- Have your car towed to a mechanic or auto repair shop specializing in engine repair. In most cases, you will not be able to fix the engine on your own, requiring the expertise of a trained professional.
- Once at the shop, the mechanic will thoroughly inspect the engine to determine the extent of the damage. Depending on the severity of the damage, the mechanic may recommend an engine rebuild or a complete engine replacement.
- If an engine rebuild is recommended, the mechanic will need to disassemble the engine and replace any damaged components, such as bearings, pistons, rings and gaskets. In some cases, the engine block or cylinder head may need to be machined or replaced.
- The mechanic will install a new or rebuilt engine into your vehicle if a complete engine replacement is recommended. This is typically a more expensive option but may be necessary if the engine damage is too severe to repair.
- After the repair or replacement, it is essential to maintain proper oil levels and change the oil regularly to ensure the longevity of your engine. Follow your car manufacturer’s recommended oil change intervals, and check your oil levels regularly to catch any leaks or other issues early on.
If you suspect the engine may be damaged from running it with no oil, you should switch the car off. An engine can destroy itself past repair in a matter of seconds. It is challenging to repair an engine without knowledge and training on its operation, so it is much better to have a trained mechanic inspect the damage and provide a suitable repair. Unfortunately, regardless of how bad the damage is, it will be an expensive repair.