Effects of Bleach in a Gas Tankby Richard Rowe
Life is full of people who wish others harm, and they certainly have their ways of seeing it done. Pouring household chemicals into other peoples' gas tanks in the name of revenge probably goes back to the first horsedrawn cart-driver Karl Benz cut off in traffic -- and the results are much the same now as they've always been.
Store-bought bleach is made up of two things: a fairly small amount of chlorine, and a much larger amount of water. Chlorine is a corrosive oxidizer not far removed from oxygen itself on the periodic table, and it causes a kind of forced chemical "burn" in anything that reacts with oxygen. On immediate contact with fuel, it "pre-burns" or oxidizes the fuel before it gets to your engine, rendering it inert to some degree. However, if bleach is going to cause an engine to stall outright, it may be more because of the massive water content than anything else. In this sense, it would have about the same effect as pouring the same amount of water in the tank. But it would take a lot of bleach to cause an engine to stop running outright.
Bleach might not have many disastrous effects in the short term, but it's utterly devastating in the long term. Being a corrosive oxidizer mixed with water, bleach can cause any kind of metal component to rust and fall apart thousands of times faster than it normally would. Try putting a metal nail into a cup of bleach sometime, and see how many days it takes to completely disintegrate. The same thing is now happening inside your fuel tank, fuel lines, pump injectors and possibly intake manifold and cylinder head. If you suspect someone has bleached your tank, do not start the car. And if you have run the engine with bleach in the tank, have the entire fuel system flushed immediately. The best you can do at this point is run a corrosion inhibiting additive in your first tankful, and hope you caught it before it permanently damaged your car.
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.