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planman · 10-26-2006, 08:14 AM

Thanks for the replies. I too am always suspicious of the worse than we thought stuff after 10+ years with yachts. However, I have several MAN mechanics from the southeast to the northeast who have worked on this boat and I have corroborated the repair procedure with them. Two of whom I trust completely. They all agree to several common factors and procedures to solve the problems:

1) Yes - This problem IS created by problemtic fuel. I had a signficant algea/dirt problem this season and ended up having the fuel polisihed, replaced all primary and secondary filters and rebuilt the SEPARs two weeks ago to elimnate the bulk of it. This was the 4th set of filters in a four motnh period of time after using the boat for a mere 30 hours furing the north season. The fuel was clean when we left but possibly the damage had been done.
2) If the injector pump fails and there are microscopic pieces of metal (from the pump itself) in the pump, then there is a strong probablitity that those pieces could get into other injectors and evetually foul them up. Two of the old injectors were fouled. This repair was quesitobale but I decided to protect a $150,000 engine with a $1,500 repair.
3) Starboard injctor pump rebuild - After speaking with all the MAN people I know, it was pointed out that since this was created from a fuel problem and both engines feed off the same fuel, it is only a matter of time until this problem would happen to the starboard engine. That said, my dilemna was - do I take the chance of traveling south next week with a potential timebomb and another fuel leak (engine room was covered in diesel when we got to dock) or go with preventative approach to protect the engines, boat and us? I decided that it was prudent to see if the starboard pump has the same problem which, if it does, leads directly to a manfacturers latent defect in the design or manfucature of these particular components. Costly yes, but safety and answers were on the top of the list.

The engines are started and run weekly.
The engine have only 1450 hours on them so it is not fatigue.
All the lines on the port engine are being replaced but not on the starboard unless that pump is contaminated as well.
All parts come from MAN but we are using rebuilts as replacements.
Cruise RPM is 1975 top end is 2350. Seldom run at top end. Don't need to do 30+ knots.
Fuel filters are changed periodically depending on the condition of the fuel in the SEPARs. If unclean in the least, all filters get changed ASAP.

As for the valves being fuel lubricated, one point that was brought up by the repairing mechanic was the new fuel emission requirements for diesel. New fuel has very low sulfur therefore less additives for lubrication. That might add to the problem and will find out as well.

There's the story, does this make more sense to you now? Still working my way through this but it is not fun and very costly.

Thoughts?

10-26-2006, 08:14 AM	#5
planman Registered User Join Date: Oct 2006 Location: newport Posts: 2	K1w1 - Tsi Av Thanks for the replies. I too am always suspicious of the worse than we thought stuff after 10+ years with yachts. However, I have several MAN mechanics from the southeast to the northeast who have worked on this boat and I have corroborated the repair procedure with them. Two of whom I trust completely. They all agree to several common factors and procedures to solve the problems: 1) Yes - This problem IS created by problemtic fuel. I had a signficant algea/dirt problem this season and ended up having the fuel polisihed, replaced all primary and secondary filters and rebuilt the SEPARs two weeks ago to elimnate the bulk of it. This was the 4th set of filters in a four motnh period of time after using the boat for a mere 30 hours furing the north season. The fuel was clean when we left but possibly the damage had been done. 2) If the injector pump fails and there are microscopic pieces of metal (from the pump itself) in the pump, then there is a strong probablitity that those pieces could get into other injectors and evetually foul them up. Two of the old injectors were fouled. This repair was quesitobale but I decided to protect a $150,000 engine with a $1,500 repair. 3) Starboard injctor pump rebuild - After speaking with all the MAN people I know, it was pointed out that since this was created from a fuel problem and both engines feed off the same fuel, it is only a matter of time until this problem would happen to the starboard engine. That said, my dilemna was - do I take the chance of traveling south next week with a potential timebomb and another fuel leak (engine room was covered in diesel when we got to dock) or go with preventative approach to protect the engines, boat and us? I decided that it was prudent to see if the starboard pump has the same problem which, if it does, leads directly to a manfacturers latent defect in the design or manfucature of these particular components. Costly yes, but safety and answers were on the top of the list. The engines are started and run weekly. The engine have only 1450 hours on them so it is not fatigue. All the lines on the port engine are being replaced but not on the starboard unless that pump is contaminated as well. All parts come from MAN but we are using rebuilts as replacements. Cruise RPM is 1975 top end is 2350. Seldom run at top end. Don't need to do 30+ knots. Fuel filters are changed periodically depending on the condition of the fuel in the SEPARs. If unclean in the least, all filters get changed ASAP. As for the valves being fuel lubricated, one point that was brought up by the repairing mechanic was the new fuel emission requirements for diesel. New fuel has very low sulfur therefore less additives for lubrication. That might add to the problem and will find out as well. There's the story, does this make more sense to you now? Still working my way through this but it is not fun and very costly. Thoughts?