Engine pickling and oil

[Dymaxion]

Quick note for those who may need to flush out and engine after drowning. Recovering a Mercruiser 3.0 that sank on its trailer during high floods/tide this spring.

Got about 7 litres of oil and water out of a 4 litre capacity. Ran until warm then drained. A fresh oil change produced pale chocolate milk coloured oil. Realizing I would need 2-3 more changes I opted to recover the oil by evaporating off the water in a roasting pan on the BBQ on very low heat. Worked like a charm, oil went back to dark colour in half an hour. My maple syrup sugaring off skills at work.

This recovery oil went back in once more, rinse and repeat. Will likely need another rinse or two. Once no more chocolate milk drains out I'll final fill with fresh.

This cut down on throwing away say 12-16 litres of oil, and saved some cash. Emphasis is on very low temp evaporation, just enough to boil off the water and not damage the oil. HTH.

[Marksman]

You will be cooking the water out the oil but any salt will stay in the oil. Me thinks I would still give another oil change or two to eliminate as much slat as possible. Still cheaper than a new engine. But great idea for saving on disposal costs.

[Dymaxion]

Originally Posted by Marksman

You will be cooking the water out the oil but any salt will stay in the oil. Me thinks I would still give another oil change or two to eliminate as much slat as possible. Still cheaper than a new engine. But great idea for saving on disposal costs.

Good point I'd missed, tx. We have an excellent oil recycling program here in New Brunswick (Canada). Anywhere that sells oil MUST accept dirty oil for recycling, free of charge and it's not restricted to only oil sold at that location. I will be taking 3 jugs in when done, looking good now, time for a fresh clean fill.

[a64pilot]

Oil is recycled in the US as well, it’s actually sold by the stations that take it, they aren’t making a killing, but because they can sell it, it’s a recycle program that works. Most all auto parts stores will accept old oil.
Oil change stations won’t usually, cause they don’t want to make charging your own oil any easier I’m sure.
I wouldn’t cook it off myself, oil is just too cheap when compared to a motor, but if it worked for you, then that is good.

[hellosailor]

In the US it varies by state. State and municipal laws often will require anyplace that SELLS oil to also take in used all, from all comers. Marinas often have a "waste oil" tank, literally a 500-gallon home heating oil tank, for waste. And gas stations often have a waste tank, for old lawnmower gasoline, used oil, etc. that they lump in all together and sell to recyclers. Unless you're in the 'burbs, where someone may be burning it in their shop heater.

[_andi_]

Farmers use(d) diesel to flush engines, running them at idle for about a minute, not revving up. Biodiesel is more hygroscopic than normal diesel btw.

I'd probably just crank during flushing it with pulled plugs / injectors while spraying WD40 into the cylinders (WD actually stands for Water Displacement).

[Cadence]

Originally Posted by Dymaxion

Quick note for those who may need to flush out and engine after drowning. Recovering a Mercruiser 3.0 that sank on its trailer during high floods/tide this spring.

Got about 7 litres of oil and water out of a 4 litre capacity. Ran until warm then drained. A fresh oil change produced pale chocolate milk coloured oil. Realizing I would need 2-3 more changes I opted to recover the oil by evaporating off the water in a roasting pan on the BBQ on very low heat. Worked like a charm, oil went back to dark colour in half an hour. My maple syrup sugaring off skills at work.

This recovery oil went back in once more, rinse and repeat. Will likely need another rinse or two. Once no more chocolate milk drains out I'll final fill with fresh.

This cut down on throwing away say 12-16 litres of oil, and saved some cash. Emphasis is on very low temp evaporation, just enough to boil off the water and not damage the oil. HTH.

Come on oil is cheap. Buy it by the boxes of gallons. Only a decent oil until you get to the final change.

[Dymaxion]

I agree, oil is cheap and well worth buying always. The insurance valuation for the motor was $7000 if scrapped. At worst $100 in clean oil was reqd. We weren't sure any of the electrics had survived their dunking, nor the pistons or rings since we couldn't access the boat until water levels dropped, almost a week of drying/rusting out post flood. So it was a quick fix with a couple of gals of oil on hand and I wanted to get the motor "dried out" as quickly as possible. Your point is well taken, a days running around in gas cost is same as the annual oil and filter change cost, yet we don't worry about fuel costs while we skimp on oil change costs. Human nature at its worst. Cheers