Hi all. Yesterday*the 330hp 6BTA Cummins in our 2003 Mainship 390 started blowing black smoke and losing power. First time it's ever smoked at all. The engine has 790hrs on it, almost all of it in fresh water.*We were 2hrs out so limped back to the marina, with the engine feeling like it was running on 5cyl. No abnormal temp. or oil pressure readings, or unusual noises.*The oil level, however, is now way up. I think it's likely*fuel contaminated since there's no evidence of water on the dipstick, and coolant level is normal. I have no diesel engine expertise (but lots of hands-on gas engine experience)*and*would like*to establish what has failed before I call in the specialists. I'm hoping someone in the group can comment on my approach to this issue, which I'm hoping is a failed/stuck injector: 1/ Drain oil and check for contaminants, both visually and by smell(presence of fuel).* 2/ change filter and refill with fresh oil. 3/ Restart and "crack" injector supply lines to try and identify bad cyl.(read about that technique on Boatdiesel forum)*4/ Remove injector and inspect/clean/get pressure tested (I believe any diesel shop can do this?) 5/ Inspect the suspect cyl. with a borescope. 6/ Pray!
There was no evidence of unusual blowby, I'll check into that more when I go back to the boat. I added a "puke bottle" to the crankcase vent in the spring so the evidence should be in there.
Needless to say this is a very troubling development and totally unexpected......the engine has been maintained to Cummins standards, the boat is propped correctly and fuel properly filtered (Racor 2micron), and stabilised during off-season. It always starts instantly and has run flawlessly up to now.
As I stated before I have no hands-on diesel experience, but I am hoping to learn real fast! Any tips/guidance from those with more experience in "the holy place" on their boats would be greatly appreciated.
Thanks',
Nick
*
There was no evidence of unusual blowby, I'll check into that more when I go back to the boat. I added a "puke bottle" to the crankcase vent in the spring so the evidence should be in there.
Needless to say this is a very troubling development and totally unexpected......the engine has been maintained to Cummins standards, the boat is propped correctly and fuel properly filtered (Racor 2micron), and stabilised during off-season. It always starts instantly and has run flawlessly up to now.
As I stated before I have no hands-on diesel experience, but I am hoping to learn real fast! Any tips/guidance from those with more experience in "the holy place" on their boats would be greatly appreciated.
Thanks',
Nick
*