Can You Use Flex Seal As Engine Oil? The Truth!

If you are unaware of what a flex seal is then it is a product that is created for bonding different metals together. It is considered to be a powerful adhesive. There has been a report that it can actually prevent water from flowing out of a bucket. It also stated that nothing can penetrate through the flex seal. At this point, you may be wondering if a flex seal can be used as engine oil.

With this product comes a warning on how you should actually use it. With that said, we don’t think it would be a good idea to pour any inside an engine.

In this article, we have explained everything you need to know about flex seal and whether or not it can be used as engine oil.

Can You Use Flex Seal As Engine Oil?

There is no doubt that you can use flex seals for certain repairs on your vehicle, and it is also known to protect different parts of your vehicle that are considered to be exposed to extreme environmental conditions.

With that said, we don’t think you should use it to fix your car’s exhaust leak. The reason for this is that these seals are usually been exposed to high pressure as well as heat.

You should not use a flex seal as a replacement for engine oils. It can damage your car engine which will do more harm than good. The reason behind this is that it is too thick.

Sealing Motor Oil Leaks From the Outside

Can You Use Flex Seal As Engine Oil

Yes, you can definitely seal motor oil leaks from the outside. You can stop the oil leak by simply adding oil leak sealant or additive to the liquid system.

Another thing you may want to keep in mind is the size of the leak. If it’s a case where there is just a small crack on the seal, then you can fix the issue from the outside.

All you have to do is pour a bottle of sealer or even a stop leak additive into the engine. Upon using the liquid sealer it can condition and soften the rubber sealer which will eventually prevent further leaks from happening. If the sealer isn’t capable of fixing the hole, then the only option is to replace the leaky seal.

Here is a list of two oil sealers that will help you fix the oil leaks without you needing to replace your car.

1. Blue Devil Stop Engine Oil Leak

The Blue Devil Stop Engine Oil Leak is a very effective sealant that is capable of working with both diesel and gasoline engines. You can go ahead and add this additive solution to your vehicle’s engine or transmission. Using this sealer it will take less than two days to get the job done.

2. AT-205 Re-Seal

You can use this amazing sealer if you have an oil leak. This looks similar to water but it is polymer oil and can be used with every fluid.

This can be used to fix all types of oil leaks. For example, if your car’s automatic transmission has a leaking from the main seal, then this sealer will get the job done.

Is it Safe to Use WD-40 As Engine Oil?

No, we don’t think it is a good idea since WD-40 isn’t capable of lubricating an engine. Over time it will break down from the heat and burn. Apart from that, it will damage all the seals that catch your oil inside your engine. This is why we don’t recommend using it as engine oil.

However, it is safe to say that you can use engine oil as a substitute for WD40. The reason being is that WD40 is a lubricating oil that has 70% kerosene and 30% light body. This is why using anything else apart from a WD40 on an engine is a good idea.

FAQs – Frequently Asked Questions

Q. Does flex seal work on the car engine?

Yes, you can definitely spray the flex seal on your vehicle’s undercarriage, wheel wells, and truck bed. You can use it to protect against rust, rocks, and debris.

Q. Is flex seal oil resistant?

Flex seal is not considered to be resistant to corrosive combustible such as gas or oil. However, experts don’t think it is a good idea to use flex seal fluid on a gas tank. The reason for this is that it may not be able to burn or leak immediately.


Flex seals tend to do a superb job on many surfaces including glass, fiberglass, plastic, aluminum, and metal. The fact Because these are often used in cars, you’ll have the ability to use flex seal for engine oil repairs.

We truly hope you find this article to be helpful!