What is this Diesel Fuel contamination thing?

[JSSailem]

So we bought our new to us 1974 Cal35 Cruiser in March of this year. Our first big boat. We struggled to get the Perkins 4.107 to run smoothly, without over heating. Went through a BMW (basic marina worker) who said he was a diesel mechanic, only to demonstrate he was more accurately an oil changer wanting to be a mechanic. Finally decided with the help of the Cruiser Forum and others that I could learn the basics and do the work myself. Got the engine running, and the overheating challenge solved (at least for now).

My wife (not really a sailboat enthusiast) and I set off on our maiden cruise. A 35 nautical mile cruise up the Puget Sound.

We got about 2.5 hours from the marina, and the motor (which had been just purring like a kitten) coughs a couple of times and dies. None of my restarting attempts were remotely successful.

Hey no problem we are a sailboat.

Raise the sails and beat upwind through minor chop. We are making good speed but we are tacking back and forth across the Sound adding considerable distance to our trip. One neat experience, while close to the west side of the sound we see a grey whale spout. For 30 minutes the whale rises to the surface, spouts a couple of times as we see his back clear the surface, tail rises out of the water and sounds to feed. This was exciting. Brought my wife out of the cabin and a smile to her face.

Meanwhile, I can see we will be running out of daylight before we make our intended harbor (Port Townsend, WA).

So we discuss heading to our secondary harbor (Port Ludlow, WA). This is why you chart your progress. Using manual charts allowed me to understand our changing conditions. We made a last tack and ran clear across the Sound from Whidbey Island to the bay entrance at Port Ludlow. It was a great sail, until the wind died at the entrance. Fortunately another sailor on a 37 foot Creelock was nearby, and in the same situation - no wind. We hailed him and told him our lack of motor issue and he offered to tow us to the marina. (What a marriage savior.) The fine folk at the marina had a stretch of dock open for us on the outside. We let go of our tow, drifted to the dock and tying up safe and sound. Smiles and thank you's all around.

Next morning I learned about the blockages of fuel flow by crud and goo in our tanks. The seller had told us about the great deal we were getting - 135 gallons of fuel in the two 85 gallon tanks. Being uninformed I did not know to ask when the fuel had been placed in the tanks. I had inspected the filters and learned they were newly changed.

Well we changed the fuel filters. Added fresh fuel to one of the tanks, which we drew down on our return trip. Cruised on our engine for 5 hours safely back to home port.

Now exploring the ideas of tank cleaning and fuel polishing. Additionally, I am going to change out the Fram Water Separator/Fuel filter with it's black case for one with a clear bowl and more easily changed filter.

All turned out ok. Wife says she will go again.
John
S/V Hadley

[Paul Elliott]

Fuel tanks accumulate water via condensation and perhaps leaky fuel-fill deck plugs, or vents. Certain types of bacteria thrive at the water/fuel interface, and also collect as slime on the tank walls. This needs vigorous scrubbing to clean up. Every few years I drain my tanks into 5-gallon cans (I have about 20 of them I use for this). If I see water or slime being pumped out that stuff goes into a jerry can that gets recycled. I then reach into the tanks through the access plate and scrub with paper towels. Once the tank walls are clean, I pour the fuel through a filter and back into the tanks. I add a biocide.

Sometimes I bring the old fuel back home to use in my tractor, and fill the boat tanks with fresh fuel.

It is possible to "scrub" the fuel in-place, without draining the tanks, but you have to be sure that you are getting all the gunk off the tank walls. This takes mechanical scrubbing, or a high-pressure jet using the filtered fuel. If your scrubbing doesn't clean the tank walls it's not worth doing, since (as you have discovered) the first time you get knocked about at sea much of that crud will end up in your fuel filter.

[Lepke]

With proper additives in the fuel and filter changes you can "polish" your own fuel.
My boat sat for 6 years before I bought it. There was about 50 gallons in the day tank and I added 20 more with Algae-x conditioner. The engines smoked until I added more new fuel, but they ran reliably. Now I use Archoil AR6200. But both kill bacteria and cause water to be dispersed so it can be burned. 6200 dissolves sludge and also is a catalyst that reduces soot and improves power. I found it because of my diesel pickup.
Back to my boat, I had no starting problems and did a sea trial of about 30 miles. I changed the filters and traveled from Vancouver Island to Astoria without any problems. While doing some remodeling 4 years later, I went into the tanks (made in 1942) and they were absolutely clean.
I also had the experience of getting mothballed ships diesels running again. The most I ever did was add a good fuel conditioner, circulate the fuel, startup on the original filters, and change the filters after sea trials. Some of the engines sat for 20 years and had old fuel in the tanks, but fuel was better then.
Fuel polishing is the hot new topic, but almost all diesels circulate more fuel than burned, so your fuel in your trip was probably filtered many times. My mains pump about 35 gallons an hour each, but burn about 5 gallons each. I have a 200 gallon day tank. So roughly every 5 hours, all the fuel has been thru the filters once.
If you don't have a vacuum gauge between your filters and fuel pumps, installing one will show when filters are becoming clogged. You should have about a 30 micron on your primary and a 10 secondary. I use a 2 or 4 micron because my fuel is clean and I have a oil fired boiler that tends to plugs nozzles. I also don't buy fuel from sources that sell very little fuel. I go to commercial fuel docks when they're available.

[boden36]

In addition to the above suggestions, consider setting up a second fuel system with its own filters and a cock that lets you change from one line to the other.
That way you can get a fresh fuel feed when the first filter clogs, and change the clogged one underway if necessary.

Regards,
Richard

[Rustic Charm]

I had very similar problems when I re-initiated a keel tank that had not been used for six years. Due to the baffles in it, I was unable to reach everywhere to clean it. I was introduced to a product called Fuel Right which has certainly stopped my clogging problems. In a few weeks I'll be slipped and will take the covers off to see what the tank looks like after a year of using it.

[EveningTide]

JSSailem- Could you tell us about the overheating problem and what was done to correct it? Thanks

[wesevans]

Sounds like you have fuel without a biocide that has set in the tank for too long without being polished. What happens is that water from condensation will provide a situation which allows the formation of a bactericidal sludge to form. This sludge will clog your filters blocking fuel flow to your engine. Have your fuel polished, tanks cleaned, add a biocide to your fuel and always carry spare fuel filters.

[OS2Dude]

You don't necessarily need to replace your separator/filter, just clean it well. We we got our boat a few months back and I had my brother help me replace the filters. (Never had an inboard, let alone a diesel before...) The separator bowl was black, as you say yours is and so full of crud the drain would not work. We took the whole thing off and found a brake shop that let us us their tool cleaner. (A small table with cleaning fluid they use to clean parts and tools with.) After a bit the bowl was clear again and the drain worked too. With a new filter it has been working great!

In our case, the engine was overheating because the previous owner's 'mechanic' (Sounds like yours...) had put an over-sized impeller in the raw water pump and it was totally fouled up. Not to mention the undersized heat exchanger that was jury rigged after it had apparently started to leak. We took it apart after replacing it with a bigger one and it was full of seaweed and bits of detritus. Added a strainer to the raw water feed as well... Now the engine purrs like a kitten and keeps a stable temperature no matter how long we run it.

(When I remember to open the ENIGINE seacock... Opened the wrong one once and the engine overheated quite quickly. Thankfully I noticed it and opened the correct seacock immediately. There are two right next to each other, one was not used at the time and had been capped off.)

[Pete7]

Wondering what my 26 year old fuel tank was like inside I took the inspection hatch off and found this:




After a lot of work with a pump, wall paper scraper and a bathroom towel this is what the tank now looks like:



My conclusion is that water was entering the tank via the fuel filler which didn't seal properly. I suspect this had been happening for some time which neither I or the previous owner knew about. Certainly the fuel filters were clean when changed each year. Oh and I have been using a home made fuel polisher for about three years which sadly wasn't effective despite regular use.

[Harding]

Never ever use biocide or polishing, its only profitol.
Use good housekeeping.
Translate with google translate from Danish to English this text: Dieselpest - www.udkik.dk

Originally Posted by Lepke

With proper additives in the fuel and filter changes you can "polish" your own fuel.
My boat sat for 6 years before I bought it. There was about 50 gallons in the day tank and I added 20 more with Algae-x conditioner. The engines smoked until I added more new fuel, but they ran reliably. Now I use Archoil AR6200. But both kill bacteria and cause water to be dispersed so it can be burned. 6200 dissolves sludge and also is a catalyst that reduces soot and improves power. I found it because of my diesel pickup.
Back to my boat, I had no starting problems and did a sea trial of about 30 miles. I changed the filters and traveled from Vancouver Island to Astoria without any problems. While doing some remodeling 4 years later, I went into the tanks (made in 1942) and they were absolutely clean.
I also had the experience of getting mothballed ships diesels running again. The most I ever did was add a good fuel conditioner, circulate the fuel, startup on the original filters, and change the filters after sea trials. Some of the engines sat for 20 years and had old fuel in the tanks, but fuel was better then.
Fuel polishing is the hot new topic, but almost all diesels circulate more fuel than burned, so your fuel in your trip was probably filtered many times. My mains pump about 35 gallons an hour each, but burn about 5 gallons each. I have a 200 gallon day tank. So roughly every 5 hours, all the fuel has been thru the filters once.
If you don't have a vacuum gauge between your filters and fuel pumps, installing one will show when filters are becoming clogged. You should have about a 30 micron on your primary and a 10 secondary. I use a 2 or 4 micron because my fuel is clean and I have a oil fired boiler that tends to plugs nozzles. I also don't buy fuel from sources that sell very little fuel. I go to commercial fuel docks when they're available.

[JSSailem]

Sure. After firing the BMW (boat marina worker) who wanted me to replace the temp gauge and temp sender, I looked in the coolant header tank. My 4.107 Perkins is what is identified as "fresh water coolant cooled". It is a closed system like the radiator on your car engine. There is a header tank that holds the coolant. It was dry - not a good sign. I filled the tank with water and started the engine. Crawling down into the engine room I saw coolant/water spraying around the front of the engine and alternator belts. Shut down the engine. Inspecting the pulleys, belts and alternator, I found seepage and rust by the water pump, a worn belt and loose bolts on the alternator.

I removed and replaced the water pump. The seal was compromised and the bearings were worn. I removed and replaced the belt. I aligned and tightened the bolts on the alternator. I replaced the coolant in the engine and header tank. I learned that the coolant system is most likely self bleeding. I filled the header tank, left the cap off, bounced the boat, heard burping/belching as a friend bounced up and down on the rail holding onto the stays. Refilled the header tank and turned the engine over. It started. No leaks. Ran engine for a few minutes. Stopped engine, checked the header tank level, refilled and felt warm fluid in the header tank. Closed the header tank cap, and started engine running it for 10 minutes no load. Temp came up to 180 where thermostat is supposed to open. Continued running the engine at the dock, secured the dock lines and kicked the engine in gear, running the engine for 45 minutes monitoring engine temps and inspecting for leaks. Temps settled at 175 and no leaks were observed.

So with a measure of confidence and a bit of adventure - pushed away from the dock and motored out of the marina and into the Sound. I motored at various rpms 1800 to 2800, watching the Temp gauge and listening for everything. Motor purred, temps stayed steady at 175. All good signs.

Best thing I ever did was to fire the BMW and with the help of this forum learn to work on my own boat.

Hope this helps.

[JSSailem]

You guys are spot on about the fungi and critters growing in my diesel. Fuel from the filter change went from clear pink to black as the filter emptied in the bucket.

The Fram water separator/fuel filter I inherited is black painted or black plastic. You can not see into the bottom section of the bowel. While there is a bleed screw on the bottom of the bowl the size of the hole only lets water escape. Any crud that may be there is trapped and eventually blocks the filter. Believe this item is a truck system or an original 1974 part.

So I plan to change this unit out for a Parker/racor 500M unit that has a clear bowl and a system hopefully a little easier to change and bleed. All comments on this plan are most welcome.

I also intend to explore the tank cleaning and polishing idea. Cleaning the tank walls and hopefully recovering most of the 100 plus gallons that are in the tanks. At the very least I know the fuel in the starboard tank is mostly new. I put 50 gallons in to assure the best possibility of getting home. Tank is listed as 85 gallon. The fuel in the port tank (estimated at 2/3 thirds full in the second 85 gallon tank) is of questionable unknown age. That fuel may need to be recycled at the local yard. Tank cleaned and then fresh fuel filled.

My reading about fuel indicated that polishing only works if it is done before the big chunks of biological critters develop. Any thoughts?

John
S/V Hadley

ps. I'll take pictures and post when I start this proejct.

[Pete7]

Actually, the ideal is the filter removes the water from the fuel so stopping any fuel bug developing.

If you have inspection hatches on the fuel tanks worth shinning a bright torch inside to see what is going on.

Pete

[Paul Elliott]

Originally Posted by JSSailem

I also intend to explore the tank cleaning and polishing idea. Cleaning the tank walls and hopefully recovering most of the 100 plus gallons that are in the tanks.

When you drain the tanks, take the fuel from the top of the tank first. The grungy stuff and water will be at the bottom, so the fuel off the top will be pretty clean. Once you start sucking up the nasty stuff that fuel should be discarded (in my opinion). It might be possible to polish it, but why risk introducing more bacteria (etc.) back into a freshly-cleaned tank? Run the clean fuel you took off the top through a filter and it should be fine to re-use. I use one of those West Marine "filter-funnels" for this:


As for biocide, I think adding it to an already-contaminated tank is a bad idea -- it's just going to make your fuel filters clog even faster. Using biocide with clean fuel and a clean tank is a good way to keep things from going bad. Do check your deck-fill fittings. Look for cracked O-rings and the like. Using a bit of silicone grease on the O-rings isn't a bad idea. You don't want to let water leak into the tank.

[GrahamHO]

Sounds like you're on the right track. I would be using a hand pump to suck some diesel from the bottom of the tank after it's been sitting a while, and repeat every so often. I would also try to use up as much as possible of the contaminated diesel before replacing with new. You can run your motor against the mooring lines at half speed in gear for a few hours if you have time. Then if you get a blockage again you're not at sea. Keep changing your filter elements fairly often until you think the problem has gone. Replace with only a little new fuel at a time so you can get rid of the old as soon as possible. There are mobile fuel cleaning / polishing contractors around where I live in Auckland NZ. I've seen them at my marina. I suppose they also do trucks etc so you could ask at a Diesel truck servicing outfit. Anything marine costs more than trucks.

Looking at that photo of the tank interior makes me wonder if there is a camera on the end of a stick that can be put in through the filler. You know, the same as doctors use for a colonoscopy!


My own attempt to stay at Port Townsend a couple of years ago was driving from The Dalles then Port Angeles and and finding Port Townsend was in the middle of a jazz festival. Then we walked the streets and had ice creams, then drove to Lacey being the closest accommodation available. Port Townsend looked a very nice town and boat friendly. It was really swinging that time.


Get your wife to take turns steering and try not to shout at her when things go wrong; unless you see a whale again. Go hour about steering and she will soon like sailing.