What is the Best Way to Store an Engine?

There is a lot of equipment out there that is only used intermittently, seasonally or stored for long periods of time. These stagnant pieces of equipment become breeding grounds for rust and corrosion. In the simplest terms, the problem all starts with water/condensation that sits on metallic surfaces that turns into rust and corrosion. Corrosion then eats away at the metallic surface. Additionally, rust that gets between two mating surfaces in motion creates scaring. This is particularly detrimental in an engine that sits idle for long periods of time.

Let’s consider what happens with the internal parts of an internal combustion engine. Under normal operations, the lubricant or Motor Oil does a good job of coating metal surfaces creating a layer that prevents water droplets from attaching to these metal surfaces. But, do you know what does the best job fighting condensation? The answer is temperature. The engine’s internal temperature gets well above the boiling point of water, so it vaporizes all the condensation. 

So, an engine that is run on a regular basis doesn’t have to worry about water. This can’t be said about an engine that is run intermittently, seasonally or idle even longer. Once you shut down an engine that has been operating at very high temperatures the battle to protect it from corrosion begins. The engine starts to cool and due to this cooling effect; it unavoidably pulls in moisture from the air. In addition, gravity will pull the oil down off the metal surfaces and into to oil pan. Over time, this will leave unprotected bare metal surfaces that condensation can attach to creating rust and corrosion. 

So how long does it take for these surfaces to become breading grounds for rust and corrosion in an engine? Well, there are a lot of variables that come into play but as a good rule of thumb, these detrimental effects will occur in any engine that is left stagnant for over 3 months. Now an old school way of handling this is to just run the engine a little every couple of months and your covered. That technique isn’t necessarily bad, but that isn’t always possible with a lot of these units. Are most of us going to go outside and actually start our lawn mowers and weed whackers every month. Or what about a boat, airplane or generator? And if you can start the engine regularly, how long do you run it in order to fully “cook off” all the moisture? You could be just adding more moisture by heating and cooling the engine over and over while spreading condensation throughout the engine. 

There is only one full-proof way to protect internal engine parts during long terms of inactivity and that is by using a Vapor Corrosion Inhibitor (VCI). I know it sounds pretty technical and something the average person can’t do but that isn’t the case and it is actually very easy. These types of products are commonly referred to as a “Fogging Oils” and can be purchased in aerosol spray cans and larger size containers for large pieces of equipment. These VCI products are sprayed through the engine intake, the spark plug holes and in the oil fill opening. These products create a vapor or fog of rust inhibitors that spread throughout the engine voids and neutralize the corrosion-causing tendency of moisture present in the air. These products work above the oil line and the vapor is continually active in closed systems. They also form a strong bond to all the metal surfaces. 

Now there are a few different manufacturers of Fogging Oils available. I’ve always used and recommend MotorStor because it meets MIL-PRF-46002 which is recommended by Continental Teledyne for the preservation of their aircraft engines. I figured, if it is good for an airplane, it must be good for my equipment on the ground. These types of VCI oils are used for storing all types of equipment that need additional protection while the equipment is laid-up. For larger applications and equipment, there is Nox-Rust VCI 10 that comes in drums and pails.

The greatest benefit you will get by storing your equipment with this technique is not only “Peace-of-Mind” that your engine is protected, but when you need to put that equipment back in-service, all you’ll have to do is add fuel and start it up.

Now if you want to store your engine with fuel in the tank, Read my article on:

How to Store Diesel Fuel and Equipment that runs on Diesel

How to Store Gasoline and Equipment that runs on Gasoline