Sealing Motor Oil Leaks From The Outside [3 Common Sealers]

Sealing motor oil leaks from the outside! Is it possible? Fortunately, Yes. You can stop an oil leak by adding oil leak sealant or additive in the fluid systems or on the affected area. 

Today, we will introduce you to three oil sealer additives that help you fix leaks permanently without removing any part of your vehicle. Turns out, we will break down- 

  • Can you seal an oil leak from the outside? 
  • Does the oil seal stop leak work? 
  • And a lot

So, stay in tune with us till the end. 

Can You Seal An Oil Leak From The Outside?

It depends on how large the leak is. If there is a small or hairline crack on the seal, you can fix it from the outside. In other words, you don’t need to disassemble any part of your vehicle to reseal the leak. 

Note: You can also read how to fix the Wheel Bearing leaking oil problem.

Just get a bottle of sealer or a stop leak additive and pour it into the engine or the transmission (it depends on the leaking seal location). When you run the sealer into the engine or the transmission, it can rejuvenate the seals on the oil seals. In short, the fluid sealer can soften and condition the rubber sealer to avoid further leaks. 

However, the sealer fails to fix the large holes. In this case, you should replace the leaking seals. 

Sealing Motor Oil Leaks From The Outside [3 Common Sealers]

This chapter will mention the three oil sealers that will help you fix any oil leaks without replacing or disassembling your car. 

1. AT-205 Re-Seal

If you have an oil seal leak in an inconvenient place and don’t have enough time to replace it, AT-205 Re-Seal will work like a charm. The sealer looks like water, which is actually polymer oil. You can mix it with almost every fluid. 

You can fix every type of oil seal with it. For example, if your car has a leak in the front main seal of the automatic transmission, this sealer will fix that. You don’t need to spend hours pulling the transmission off. 

Just pour the sealer into the transmission and drive your car for hours to make a leaking seal perfectly. You can drive your car a thousand miles before replacing the seal if you reseal the leaky seal with this additive. 

2. Blue Devil Engine Oil Stop Leak

Blue Devil oil leak sealant also works like a champ. It is compatible with both gasoline and diesel engines. Just add this additive solution into your car engine or transmission (anywhere the leaks come from). It takes less than two days to seal any leaks permanently. And the best part is– this additive brings no damage to your vehicle. 

3. Permatex Spray Sealant Oil Leak

This spray sealant for oil leaks also works. We had a leak between the oil pan and the block. So, we get this oil pan leak sealer and spray 3-4 coats on the affected area of it every 1-3 seconds. Make sure you clean the affected area before applying it. Then, leave it for 45 minutes to let the sealant set. After that period, start your engine and check underneath your car for oil dripping. We hope you will find no oil drippings as we found nothing. 

Does Oil Seal Stop Leak Work?

Yes, oil seals stop leak works and fix small leaks. Generally, the oil seal leak revitalizes the gaskets and seals to minimize the gaps that cause the oil to leak. It takes at least 2-3 days for the oil leak sealant to stop the leak permanently. So, it would be best if you drive your car for several hours after applying the oil leak sealant.  

Keep in mind, that the oil seal stop additive is specially designed to fix small leaks. It fails to fix the large hole or an engine that gets damaged severely.  


Can you Flex seal an oil leak?

Of course, you can Flex seal an oil leak if you don’t mind wasting your money. The Flex seal will not bring any luck to you as it fails to stop the leak. Of course, the leak may stop for a while. But it will come back again. 

Can you seal a head gasket leak?

Yes, you can seal a head gasket leak from outside. Just pour the BlueDevil or AT-205 Re-Seal into the radiator. Then, drive your car for several hours, which will fix the leak permanently. 

Can you seal a valve cover without removing it?

Yes, you can seal a valve cover without removing it. Just clean the valve area evenly and spray the Permatex Spray Sealant into the affected area. Let the spray sit by leaving it for 45 minutes, which will stop the leak.

Does Blue Devil Stop leak work?

Yes, Blue Devil Stop Leak works and fixes leaks in any fluid system. Just pour it into the fluid system and drive the car for several hours. 

Is BlueDevil a permanent fix?

Yes, it’s a permanent seal that seals almost every oil leak in any fluid system. 

Does permatex spray sealant work? 

Yes, it works. We recommend you use it by combining it with other products like engine oil or fluid to reseal any leaks. 

Does thicker oil help with leaks?

Unfortunately, thicker oil doesn’t help with leaks. We recommend you use the oil sealant we mentioned to fix any small cracks or holes in the seal. 


Sealing motor oil leaks from the outside will be easy & effective if you have the right oil sealant at your fingertips. We recommend you use any of the sealants we mentioned above. They will help you fix the small hole or leak permanently without replacing the parts. However, it would be best to replace the leaky seals if you find a large hole there. 

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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