Re: [Amel Yacht Owners] Re: Onan Raw Water Cooling System Maintenance

Danny and Yvonne SIMMS

Hi Bill,

my TMD 22 had clean oil right through to the next change, as did the 30hp Volvo I had in my previous boat. In my experience unique among diesel engines where the normal is black oil after the first run. Nothing wrong with those engines but these Volvos are special. I put it down to no blow past the piston rings and I was always proud of my clean oil.



SM 299 Ocean Pearl

On 27 November 2018 at 03:31 "greatketch@... [amelyachtowners]" <amelyachtowners@...> wrote:


Bill S.,

Black oil in a Diesel engine is totally normal, and nothing to worry about. Even the best tuned Diesel engine will produce a small amount of soot when running, and the tiniest bit of blow by the piston rings, and the oil is instantly black. This is very different from a gasoline engine where soot indicates a cumbustion problem.

Do not let anybody sell you an engine cleaning just because your oil is black. The best thing to do if you are concerned about the condition of your oil is to have it lab tested. It is fast, and not at all expensive. That will tell you if it has normal levels of soot and other contaminants or if something is wrong. The best thing of all is to do such testing routinely so you can see changes with time.

Bill Kinney
SM160, Harmonie
Fort Lauderdale, Fl, USA



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