[planman]

I have a 2000 65' Viking Sport Cruiser with 1050 Man's. Never had major problems with the engine(s) until last week. On the way to Florida, we discsovered a fuel leak on the port engine. Called a mechanic and he thought it was a minor fix. It turned out to be a major problem with the injector pump having hairline cracks in two of the delivery valves. Pump came off, sent to Florida for rebuild and discovered that the pump was filled with contaminants (metal shavings) which caused the need to replace the injectors and high pressure fuel lines. Learned that this is all caused by signficant fuel flow problems. Now have to rebuild starboard injector pump. Has anyone ever encountered this and what do you know about this? Luckily we have a pro working oon the engines.

[K1W1]

Hi,

I am always suspicious of the claims of "oh it's much worse than we thought" once a major component is removed and taken away for inspection.

"hairline cracks in two of the delivery valves." I have never heard of this this

"Pump came off, sent to Florida for rebuild and discovered that the pump was filled with contaminants (metal shavings)" were these metal parts of the delivery valves themselves?


"Which caused the need to replace the injectors and high pressure fuel lines."

If you had anything larger than Fuel passing through the Injector Orifices they would quickly become blocked and the engine would stop. The Fuel Lines are just tubes why couldn't these be blown through?

"Learned that this is all caused by signficant fuel flow problems."

What caused these problems? The Delivery Valves are Fuel lubricated so there is a potential for metal to metal contact.

Has anyone suggested or tersted the quality of your fuel and the possibility you may have a fungus contanmination problem which has led to the breakdown of the chrome of the Delivery Valve and Injector Plungers?

"Now have to rebuild starboard injector pump." That's unlucky.

"Luckily we have a pro working oon the engines." I hope so for your sake!

Please don't forget to post back when it's all sorted out so others may benefit from your experiences.

[TSI AV]

Hi,

Many things can happen, if there are metal particles in HP fuel pump...
And there are so many reasons, how those pieces can get in...

1. Please note, that most mono-block pumps need complete overhaul / adjustment at appx. 15000 - 16000 rhrs.
Good ones can make up to 30000 rhrs.
2. Probably engine was stopped for a long period before started ?
3. Just in case, check pump's inlet/outlet lines and filter cartridges, day tank.
4. Sometimes pump is combined with governor, problem can be there.
5. Make a good fuel analysis.

Could be great, if You post more information / pictures / description of Your system.

Engine's RPM ?
Fuel cartridge cleaning / replacement interval ?
How high is a day-tank, compare to HP pump ?
How old is Your MAN ?

What is pump's maker ? BO....? KI....? L'o.....?

rgds,

Andrei

[K1W1]

Hi,

He said in his post that it was 2000 yr boat so I would assume that these are the original engines.

Your point about the engines not being run for a longtime is along the same line as my one about the fungus contanination of the fuel especially if the boat has been sitting and had some water in the bottom of the fuel tanks there is a good chance that it is infected with.

[planman]

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?

[K1W1]

Hi,

Thank you for the detailed response. It is something appreciated by all members and something that sadly not everyone does.

The fungus grows in the interface layer between the fuel and any standing water in the tanks, you might have already filled the delivery valves etc with this gunk when you were doing your regular runs. The sulfur in the fuel can attack the metal components in the fuel system.

The chrome on the fuel pump plungers whilst being very resistant to wear is very suseptable to being attacked by this type of acidic mixture.It basically just peels off in minute pieces.

When you had the fuel polished did you also have the tanks and fuel lines cleaned out?

If you don't use any sort of fungicide in your fuel it is certainly something you should consider.

I agree 100% with you thoughts on prevention rather than repair in relation to the other pump, hopefully it won't be as badly affected as the one you have had apart already.