Engine Ran Without Oil Now Knocking [Know Possible Risk]

The engine ran without oil, now knocking! Yes, it’s the result of running your engine without oil. The presence of oil in your engine and its distribution is a must for continued engine operation. If the level of oil gets low, your car engine will produce a knocking noise due to a lack of lubrication. The internal moving parts of your engine will slap each other if there is no or too low oil and make the slapping noise. 

engine ran without oil now knocking

Here in this article, we will break down the reasons that are responsible for the knocking sound and what happens if you start the engine without oil. So, continue to read till the end. 

Note: You can also read Oil on the camshaft position sensor.

Engine Ran Without Oil Now Knocking [Reasons Behind A Knocking Sound]

Oil plays an important role to operate your engine smoothly by lubricating it. The engine oil lubricates every internal part of the engine. It enables moving parts like gears and drivetrain to handle the constant exposure to other metal parts without breaking them down.

If you don’t put oil in it or there is too low oil level, these moving parts lose their protection and get worn out immediately. Due to lack of lubrication, each of the moving parts slaps each other and produces a knocking sound. 

If your car runs out of oil and you restore the oil but it’s knocking, we bet you have done major damage to your engine. In this case, replacing the entire engine is the only option, which will leave a dent in your wallet. 

We recommend you check the oil level and don’t allow it to go below the recommended level. Also, maintain the oil change interval recommended by your car manufacturer.

Typically, changing and lubing your engine at 3500 miles is a standard rule to follow. However, some vehicles recommend you change the engine oil between 7000 miles. 

What Dangers Can Happen If You Start An Engine Without Oil?

Starting an engine without oil is certain to cause damage. Without oil, the internal moving parts of an engine lose lubrication. It means each of the parts of your engine loses their protection and they get worn out. If you start an engine without oil, all you have is the shell of your car without an engine. 

When the engine oil goes below the acceptable level, your engine will get overheated and something will burn out inside it. For example, the bearing on the shaft will get damaged if the oil level gets too low than the recommended level your driveshaft needs.

Because of the low oil level, bearings will go out of round and they become eccentric instead of orbiting in a circular manner. Consequently, they slap the side of their carriers. Thus, your engine makes a slapping noise. 

Indeed, a worn-out engine is a result of starting it without oil. So, never think twice to start your car engine without putting oil into it. 

How Do You Know If Your Engine Is Damaged Without Oil

The following signs will let you know your engine gets damaged without oil.

  • Your engine will produce a knocking or grinding noise if there is no oil in it. The internal moving parts of the engine will move roughly due to lack of lubrication and produce slapping noise.
  • Burning oil smell is also an indication that tells you about the potential engine damage. If you smell the burning oil inside your vehicle, turn off your engine and check for the oil leak. Don’t dare to start your engine if the oil level is too low. 
  • Low oil level is responsible for the lack of lubrication, which creates extreme friction between the moving parts of your engine. As a result, your engine will get overheated. You can even find smoke coming out of your hood. 
  • Internal engine parts will grind, slide, and scrape each other until your car engine stalls. 

Will Adding Oil Stop Engine Knock?

Your engine will make a knocking noise if your engine gets run dry of oil. Adding oil to your engine may stop the engine knock. However, we don’t believe it will stop the knocking sound as your engine is already damaged. 

Bearings, cylinder walls, and piston rods will have developed any number of failings if your engine makes a knocking noise. Putting or adding oil into your engine will mean nothing to your engine as the moving parts have already been damaged. 

We suggest you take your vehicle to a mechanic who will fix the engine issue by inspecting it. 


Your engine will make a grinding noise if you run the engine without oil. Yes, you can run it without oil but the effect of it will be very damaging. You can roughly operate your car for 30 minutes without oil and it will break down your engine completely. 

So, it’s better to check the engine oil regularly and maintain the oil change interval. If the level of oil gets too low, don’t start your engine unless you add oil to it. Don’t hesitate to go to a mechanic if your engine makes a grinding noise. 

About John M

John contributed as a technical head at an automobile company just 2 years after his post-graduation in Automobile Engineering. He loves to lead a free life, so he left his job & started blogging. Now, he does research on every automotive problem, part & product and seeks a better solution & best products & shares his findings with his readers to help them as well as to minimize their struggle.

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