[C320-list] Diesel Filter Changing Intervals

[Joe Luciano]

> 
> Recently, there were a couple of email strings in regard to changing diesel engine filters and upgrading filters on the C320.  I have some recent experience that I wanted to mention, as well as interest in others experience and practices.  So, my C320 is a 2005 model that I’ve had since new.  In the past 15 years, she’s been roughly 8,000 nautical miles with roughly 1200 hours on the Yanmar 3YM30.  Initially, I was changing fuel filters yearly or every other year, but finding that I was actually changing very clean filters.  So, I started extending my intervals.  While they are easy enough to change and bleed, I find the whole process fairly messy, expecially given the limited space under the aft bunk as others have discussed.  I live in the Pacific Northwest and our marina fuel in the San uan and Gulf Islands is particularly good, clean and seems to turn over frequently.  I often top off my fuel with a 6 gallon jerry can, from my local gas station.  I keep the fuel topped off, especially in winter when I don’t use the boat much and I use a typical additive for diesel fuel.  
> 
> I just finished changing my filters yesterday after a 6 year run and 400 engine hours.  I did find a small amount of sediment in the filter, but nothing surprising given the run time.  It was not a shocking amount that would have me think I pushed it far too long.  I am by nature a conservative guy when it comes to preventative maintenance.  What I saw looked like the interval was about right.  In addition, during the 6 year run, I never once had to drain anything off the bottom bowl of my Racor filter.  Had I seen debris in the bowl, I obviously would have changed filters much earlier.  I use the 10 micron Racor filter, and basically had a clear bowl for the entire run.  Upon disassembly, there was a little bit of sediment along one edge near the drain cock, but that was it.  I watch the drain bowl regularly when running the engine and it has been my guide for extending the interval.  In terms of the secondary filter, it was in pristine condition.  I debated on changing it at all, but I did change it while I had it open.  But, next go around I may only change the secondary every other Racor replacement…..
> 
> My one comparison for extending the interval has been with my Mercedes Sprinter RV.  The RV has a turbo diesel engine and while I know it isn’t marine service, the conservative people at Mercedes recommend changing fuel filters every 20,000 miles.  Well, 20,000 miles driven at an average of 50 miles/hr just happens to work out to about 400 engine hours.  And, I just did that math this evening….Considering the wide variety of places I’ve bought fuel for the RV all across the country, while it’s not in marine service, it doesn’t seem like I’m totally crazy in regard to my boat engine intervals.
> 
> Lastly, in regard to the fuel tank in my boat, I’ve never had it professionally cleaned.  It’s an aluminum tank, 15 years old.  I have tested for gunk a couple of times when my sending units went out on the tank and I had to replace them.  Each time, I took a hand siphon and put it down to the lower edge and corners of the tank, sucking fuel off the bottom.  I was able to get a very small amount of gunk off the bottom in that area, but after that, I could only find clean diesel.  So, I feel pretty good about my tank being clean and I’ve been able to keep it that way.
> 
> So, my questions to the group:
> 
> 1. Am I crazy to extend my interval for changing fuel filters to 400 engine hours?
> 
> 2. What frequency do you change your filters?
> 
> 3. What am I missing?


Joe Luciano
Second Wind
#1024