¿What happens if I use an alkaline degreaser on the motor of a car?

Question

Do it have any consecuence in a short time, or a long time? Im talking about a degreaser based on sodium hidroxide and sodium metasilicate. Thanks

Answer 1

This would be a very bad idea if one had an aluminum engine block. Aluminum and lye (sodium hydroxide) react violently. I doubt there would be enough lye to actually eat through the block, but it would be badly corroded. The worst damage would most likley be caused to any small aluminum fasteners, rods or threaded pieces on the engine. Also, lye will ruin chrome plated surfaces. Alkaline degreasers are designed to be used on cast iron or steel. Disassembled engine parts which are not aluminum are probably what these sorts of degreasers are most efficiently used for. They would probably be very useful with valves, since these are hardened steel and accumulate a thick carbonized crust. Lye is the main ingredient in oven cleaner and is good at cleaning burned steel surfaces. The best block cleaners are probably solvent based. Methylene chloride is a non-flammable solvent which is very similar to dry cleaning fluid. Used with adequate ventilation, it might be a good way to clean a block which is in place. Care must be taken to keep solvent away from plastic and rubber however, since it might either corrode them or make them brittle. Solvent will probably be hard on gaskets if it soaks into them, but this would require constant exposure. The solvent will tend to run off the block and dry immediately. Of course the really cheap approach to block cleaning is using ordinary gasoline, but there is a real danger of fire involved - not to mention it smells awful. If this is tried, I suggest letting the engine dry at least 24 hours before starting it. Gasoline will accumulate in crevices and can ignite when the engine heats. Engine fires can quickly distroy an entire car. Whatever is used to clean a block, make sure the engine is cold before cleaning it. Avoid using a water hose on a hot block to cool it because its really hard on the gaskets and could even warp the cylinder heads.

Answer 2

If you simply clean the outside of the engine, it should not have any problems.

I would not recommend putting it into your gas tank to try to clean the inside, however.