Hello all, quick introduction. I am a Cummins certified Diesel engine technician with extensive experience in the diagnostics, repair and rebuilding of cummins on road engines. Ironically I own a volvo penta gas boat. 
The boats power plant: 2007 Volvo Penta 8.1 GI (300) Hrs. mated to a 2007 Volvo Penta DPS-A Outdrive.
The issues at hand: After a 120 mile, 15 hour fishing trip I hauled the boat out and brought it home on the trailer to wash the boat. Upon inspection I found sticky/milky oil accumulations around the inside propeller. While running the engine there is milky oil/water washing off the props. immediately I thought the prop shaft was leaking. I checked the dipstick, oil level was full and clean. I removed the props, inspected the seal, ran the engine, no leaks from the seal. Drained the fluid, very little if any water in the gear lube. refilled with new oil and inspected for leaks on the lower unit. Nothing.
But wait! theirs more! Re-launched the boat, did a local fishing trip and about an hour later, low engine oil pressure (10 PSI) and reduced power mode.
Shut off the engine, inspected the bilge (no leaks) and checked oil level. 3 quarts low! Oil was full an hour earlier when I launched. Topped off the oil and brought it home.
Doesn't the engine exhaust ONLY flow out of the exhaust outlet on the DPS-A and not through the propellers? If the engine was burning oil wouldn't the out drive exhaust outlet be oily/smoky when running? It appears that I have a leaky valve guide seal but I want to rule out any out drive issues first.
The boats power plant: 2007 Volvo Penta 8.1 GI (300) Hrs. mated to a 2007 Volvo Penta DPS-A Outdrive.
The issues at hand: After a 120 mile, 15 hour fishing trip I hauled the boat out and brought it home on the trailer to wash the boat. Upon inspection I found sticky/milky oil accumulations around the inside propeller. While running the engine there is milky oil/water washing off the props. immediately I thought the prop shaft was leaking. I checked the dipstick, oil level was full and clean. I removed the props, inspected the seal, ran the engine, no leaks from the seal. Drained the fluid, very little if any water in the gear lube. refilled with new oil and inspected for leaks on the lower unit. Nothing.
But wait! theirs more! Re-launched the boat, did a local fishing trip and about an hour later, low engine oil pressure (10 PSI) and reduced power mode.
Shut off the engine, inspected the bilge (no leaks) and checked oil level. 3 quarts low! Oil was full an hour earlier when I launched. Topped off the oil and brought it home.
Doesn't the engine exhaust ONLY flow out of the exhaust outlet on the DPS-A and not through the propellers? If the engine was burning oil wouldn't the out drive exhaust outlet be oily/smoky when running? It appears that I have a leaky valve guide seal but I want to rule out any out drive issues first.
