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Conference unifix::sailing

Title:SAILING
Notice:Please read Note 2.* before participating in this conference
Moderator:UNIFIX::BERENS
Created:Wed Jul 01 1992
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2299
Total number of notes:20724

1548.0. "Perkins engine problems" by RECYCL::MCBRIDE () Mon Jul 02 1990 12:14

    I think I may have a newly developed problem with our Perkins diesel
    (4.236) which I could not find elsewhere in the file.  While at Block 
    Island this weekend, I checked the raw water filter for the engine which
    required closing the seacock.  I neglected to open it back up again and
    ran the enigne without raw water circulating through the cooling
    system.  A check over the side to make sure water was coming out the
    exhaust quickly alerted me to what I had done.  I scrambled into the
    engine compartment and opened the seacock which immediately produced
    alot if white smoke from the exhaust but subsided after about 15
    seconds.  I do not think I did any damage to the engine since the
    coolant system is the closed loop heat exchange variety.  I am afraid I
    may have cooked the impeller in the raw water pump attached to the
    transmission housing (?) and reduced its flow.  Are these things usually 
    a go or no go proposition?  The other thing I noticed is that under way, 
    the engine would not rev up over 1300 RPM in gear.  Out of gear, it idled, 
    and revved up through the useful range fine.  Under load it just did not 
    seem to want to rev higher than 1300 regardless how much fuel I gave it.  
    These two things may be unrelated but if anyone has some Perkins
    experience or knowledge, a little info would be appreciated.  My
    partner and I are both planning on vacations this month and I would
    hate for us to have problems while we are out.  
    
    Brian
T.RTitleUserPersonal
Name		DateLines
1548.1A sad tale from experienceAIADM::SPENCERCommuter from the other CapeMon Jul 02 1990 14:0225
>>>   ...opened the seacock which immediately produced alot if white smoke 
>>>   from the exhaust but subsided after about 15 seconds.  

Given that the heat exchange manifold might have been rather hot by the 
time the cool seawater did reach it, could that have been a cloud of 
steam?

Is it possible that heat exchanger cracked under the cicrumstances?  Ours 
did once under similar circumstances, and raw water made its way back to 
the engine.  Which then was not the same till we replaced it.  :-(  
Interestingly, in our case the water got into the freshwater side of
things *after* shutting down the engine, when the cooling resulted in
contraction of the system, pulling in the seawater on the engine side of
the anti-siphon loop. 

Another symptom of insufficient cooling we unfortunately discovered was 
that the engine didn't have much power.  The mechanic told us he thought 
the block expansion from the higher heat had produced significantly more 
internal friction in the cylinders.  It worked, but poorly, and probably 
not for long.

(For your sake, I hope it's just an coincidentally dirty fuel filter, or 
other as-easily-fixed problem!)

J.
1548.2Mystery solvedRECYCL::MCBRIDETue Jul 10 1990 10:5620
    Mystery solved.....I think.  I checked the raw water impeller thinking
    I would find a ragged mess but lo and behold, it was in fine shape.  
    All of the vanes were intact and showed no signs of abuse.  I think I 
    was real lucky on this one.  Checking the oil, and coolant showed no 
    signs of migration in either.  Mystery of low revs in gear remained 
    though.  I had noticed that the fuel pump shut off lever was sticky due 
    to a binding cable leading to the console.  It was to the point where 
    I needed to open the engine compartment and manually spring the lever 
    back into position to start the engine.  Liberal amounts of the miracle 
    cure, WD40, seemed to have somewhat of a positive effect on the 
    operation.  I suspect the cable needs to be replaced or taken out and 
    lubed.  After fiddling with this for a while, we finally left the
    mooring.  I noticed a significant increase in the ability to rev up
    in gear.  I have concluded that the fuel injection pump was not able to
    deliver enough fuel because it was being impeded by the shut off 
    mechanism slightly.  
    
    Brian