Join Date: Jun 2011
Location: somewhere south of civilization
Thanked 176 Times in 167 Posts
Rep Power: 6
Salt Water in the Cylinders
Twice now we have gone to start the Perkins 4.236 and it has had salt water (I tasted it) in the cylinders. The 1st time we took off the riser (exhaust elbow) and found no problems, so we just cleaned things up a bit and reassembled everything. Not finding a problem, we had not fixed anything, so we hoped it was a boat gremlin.
It started and ran fine for a few days then water again; no surprise.
This time we took off the exhaust manifold as well and pressure tested it to 30 pounds and it was fine. Because of its design, the riser could not be pressure tested so we took it to the local ship yard and they cut it open and again, found no problems at all.
Our overboard engine exhaust is well out of the water and we were actually only re-anchoring so we ran the engine just a few minutes the day before the second time. There is one of those black aqua-lift silencers in the exhaust line, near the transmission. The fresh water is fine, no leaks or water missing or bubbling in the header tank when running. No steam out the exhaust, nor smoke, white or black. There is no water in the oil nor in the transmission, so neither of those coolers could be at fault. Engine does not overheat, nor run particularly cold (about 170). Salt water goes through the sea strainer, then the pump, into the exhaust manifold, then into the heat exchanger and finally into the riser and into the exhaust. No where else does salt water get near the engine block or cylinders. This is not a new installation; it's been working fine for years.
Obviously, this is a really big deal as we will never know if the engine will start.
I am at a complete loss. I cannot think of anywhere else salt water could possibly enter the cylinders.
Last edited by capta; 03-11-2013 at 02:18 AM.