Water Mist= Sulfuric Acid

[SPANKY6.5ER]

I was talking with an old timer master diesel mechanic and asked his thoughts on the diesel water mist and he said that the water mixed with the sulfur in the diesel fuel had in the past created sulfuric acid that pitted or became corrosive to the pistons, shortening the life of the engine. However, with the newer low sulfur diesel he didn't know if it would be a problem today. I'm wondering if anyone has any first hand knowlege or expericence with the long term effects of water mist on their engines???

[More Power]

The current ULSD fuel is as close to zero sulfur as the oil companies can get it. The only reason the limit now is 15ppm sulfur is because of residual in the distribution system. The fuel itself is basically zero as it is refined.

We used to consider sulfur reactions in the motor oil (due to blowby) more than anything else. However, I do know that water can etch cast iron. Cast iron is microscopically porous. Molecules of water turning to steam in a pore can etch the cast iron. The cavitation erosion of the cyl walls in the Navistar 6.9 & 7.3 was thought to be due to this phenomenon. And, I saw this once on a 6.2L cylinder head that had been run for a long time with a head gasket leak - that very slowly leaked coolant into a cyl. The head deck over that cylinder was pretty cratered looking.

Jim