New to forum. I have twin 200 HP Volvo TAMD 41P in my boat. Both were completely rebuilt in 2011 with all Volvo OEM parts - new pistons, liners, rings, etc. Used the boat for a year (about 100 hours worth) with no problems. Then, pulled boat and it sat on a trailer in my lot for 1.5 years. Now, trying to get her running again.
Launched boat last week and did a sea trial. Observed the Port engine max'ing out at 2400 RPMs. Starboard engine ran perfect. Noticed the port engine turbine was frozen - probably from sitting for long time. We tried to free it with socket wrench and broke the nut and shaft - I know, stupid move.
Had turbo rebuilt and reinstalled. Sea trial again. Boat ran great - smooth, no smoke, both engines max'ed out at 3600-3700 RPMs, good temp around 160 degrees. Oil pressure at cruising (2800 RPMs) was 60 to 70 PSI. Port engine was slightly higher (70 PSI) vs. 60 psi on starboard. Thought all was good. But then,
Observed small but continuous oil leaking from exhaust side of turbo and rear main seal. Noticed crankcase pressure by removing oil fill cap and holding hand over the hole. There was pressure from breather 1/4" tube also that I have routed to air filter on turbo compressor. The guy who rebuilt the turbo said that crank case pressure was not allowing turbo oil return to drain so it leaked out the tubo exhaust side. I removed the return line from the turbo, put my finger over the return, and started engine. I felt hi pressure from the turbine return (should be low pressure gravity return, right?) and could not hold closed - oil blew out under pressure. So, my reasoning was that the turbine pressurized return was cause of crankcase pressure - turbine problem. But, turbine guy says it is an internal engine problem and his recently rebuilt turbine is fine.
Next tested compression: 1 was 475 PSI, 2 was 460 PSI, 3 was 475 PSI, 4 was 400 PSI, 5 was 450 PSI, and 6 was 500 PSI. My diesel mechanic thinks turbo rebuild may be bad and the source of turbo oil leak and crankcase pressure. Turbo rebuild guy thinks there is an internal issue (blowby?) with engine causing crankcase pressure which in turn is blowing oil out rear main seal and not allowing turbo return to drain fast enough (hence if leaks into exhaust).
Any thoughts or suggestions? Anything to do to get more clues. I'm still hopeful I don't need to rebuild engine but cylinder 4 has me worried.
Thanks. Joe
Launched boat last week and did a sea trial. Observed the Port engine max'ing out at 2400 RPMs. Starboard engine ran perfect. Noticed the port engine turbine was frozen - probably from sitting for long time. We tried to free it with socket wrench and broke the nut and shaft - I know, stupid move.
Had turbo rebuilt and reinstalled. Sea trial again. Boat ran great - smooth, no smoke, both engines max'ed out at 3600-3700 RPMs, good temp around 160 degrees. Oil pressure at cruising (2800 RPMs) was 60 to 70 PSI. Port engine was slightly higher (70 PSI) vs. 60 psi on starboard. Thought all was good. But then,
Observed small but continuous oil leaking from exhaust side of turbo and rear main seal. Noticed crankcase pressure by removing oil fill cap and holding hand over the hole. There was pressure from breather 1/4" tube also that I have routed to air filter on turbo compressor. The guy who rebuilt the turbo said that crank case pressure was not allowing turbo oil return to drain so it leaked out the tubo exhaust side. I removed the return line from the turbo, put my finger over the return, and started engine. I felt hi pressure from the turbine return (should be low pressure gravity return, right?) and could not hold closed - oil blew out under pressure. So, my reasoning was that the turbine pressurized return was cause of crankcase pressure - turbine problem. But, turbine guy says it is an internal engine problem and his recently rebuilt turbine is fine.
Next tested compression: 1 was 475 PSI, 2 was 460 PSI, 3 was 475 PSI, 4 was 400 PSI, 5 was 450 PSI, and 6 was 500 PSI. My diesel mechanic thinks turbo rebuild may be bad and the source of turbo oil leak and crankcase pressure. Turbo rebuild guy thinks there is an internal issue (blowby?) with engine causing crankcase pressure which in turn is blowing oil out rear main seal and not allowing turbo return to drain fast enough (hence if leaks into exhaust).
Any thoughts or suggestions? Anything to do to get more clues. I'm still hopeful I don't need to rebuild engine but cylinder 4 has me worried.
Thanks. Joe