Cloudy diesel

Jacana

Jacana

Active Member
Joined
12 Jun 2005
Messages
60
Location
Derbyshire
Visit site
I am plagued by cloudy diesel which I have been unable to clear by the normal methods such as fuel treatment, draining off the water etc. My Malo 38 had a 250ltr tank under the forepeak berth and the usual de-watering filter prior to the main engine filter.

Unless I am on long passages the tank capacity is more than I need but I try to keep it fairly full. Nevertheless it is prone to water condensation and I drain any water off as it appears.

I treat the fuel with a anti water chemical at the beginning and end of each season but have been plagued by severe cloudiness or milkiness in the filter glass all this year. There is no visible water at the bottom of the glass. I have motored more than usual this year and used about 300 litres so far. I have changed the filters twice which resolves the problem for a short while only.

Any thoughts?

Brian
 
There has been quite a lot of this here in Mexico during the last year or so and locally the cause has been an additive designed to kill/prevent microbes in deisel. If you are using any additives I would advise discussing this with the supplier/manufacturer as a first step.

Paul
 
Have asked my Hubby who is in the Fuel biz and he said : Cloudy fuel can be due to emulsification of water / oil - which is increased by use of water dispersants commonly sold as water treatments for diesel. Or it can be due to parafinic parts of the fuel dropping out and clouding up the fuel.
He suggests taking a sample doing 2 things in this order :
a) Warming the fuel and see if cloudiness dissapears with warmth and mixing.
b)adding petrol to it and see what happens to the cloudiness if warming doesn't clear it.

He mentioned that years gone by - he had a large amount go cloudy in India for water dispersant reasons, a complete surprise at that time. Usually it's seen when summer diesel is kept over winter and the cloud point is passed.

I'm sure as he says - other experts will make their comments.
 
I suspect that this is the result of using water dispersant additives that effectively hold the water in a stable emulsion thus preventing free water dropping out. You therefore have "wet" diesel but should not get the problems associated with free water in fuel. Wet diesel is not good for the fuel system however.

Another source of cloudiness in diesel is wax crystallising out of fuel at low temperatures. This can lead to filters blocking and consequent fuel starvation. Unlikely to be the source of your current problems unless you are sailing in cold climates - August has been lousy in the UK but not that bad!

I suggest you need to find ways of keeping the fuel in your tank dry or installing some sort of effective water separation stage in your filtration system. Have you got a true low point drain? Is the fuel take off well above the bottom of the tank? Try and avoid using water dispersants - they may cure some symptoms but do not cure the problem.
Morgan
 
Surely Morgan has hit the nail here - its your treatment that is causing the cloudiness by emulsifying the water. Presumably when you change the filters they pick some of it up but then get saturated which is why it stops for a short while only.

You have a separator before the final filter, so I'd just let that do it's job; stop using the additive and drain off the water from time to time - usually an easy job. The diesel actually going into the engine will surely be cleaner that way.
 
I picked up a batch of diesel which was cloudy, blocked the filters so added a bugkiller which made no difference.
I had been using Irish green diesel and then red so presumed that the milky colour was due to this mix, not so.
When I changed the filters I noticed a hard calcium like deposit which had at the bottom of the fuel bowl.
It later claimed the injectors which proved to be very expensive so dumped the fuel, new nozzles on the injectors, cleaned the tank and now is well once again. Still baffled why the deposits, any ideas?

Neil
 
[ QUOTE ]
Surely Morgan has hit the nail here - its your treatment that is causing the cloudiness by emulsifying the water. Presumably when you change the filters they pick some of it up but then get saturated which is why it stops for a short while only.

You have a separator before the final filter, so I'd just let that do it's job; stop using the additive and drain off the water from time to time - usually an easy job. The diesel actually going into the engine will surely be cleaner that way.

[/ QUOTE ]

Thanks. Seems that my post is ignored for diagnosing this first ? I'll tell hubby - no wonder he refuses to post himself on here. Credit where Credit due please. /forums/images/graemlins/wink.gif
 
[ QUOTE ]

Thanks. Seems that my post is ignored for diagnosing this first ? I'll tell hubby - no wonder he refuses to post himself on here. Credit where Credit due please. /forums/images/graemlins/wink.gif

[/ QUOTE ]
Fair comment. Apologies. /forums/images/graemlins/blush.gif
 
[ QUOTE ]
[ QUOTE ]

Thanks. Seems that my post is ignored for diagnosing this first ? I'll tell hubby - no wonder he refuses to post himself on here. Credit where Credit due please. /forums/images/graemlins/wink.gif

[/ QUOTE ]
Fair comment. Apologies. /forums/images/graemlins/blush.gif

[/ QUOTE ]

Thanks, just a little touchy lately. Hubby keeps digging at me for staying here !
Back to the water in diesel - there are de-emulsifiers available to actually force the water to drop out. Hubby uses them I know in line of biz. As I hear from him, having the water suspended or as enulsion in the diesel causes not only severe hydraulic stresses, but loads of other related problems for an engine or unit. Come winter the suspended water will ice-up causing serious problem to fuel lines and system, in some cases splitting the line. Of course here we are talking more of shore based as boats generally do not drop too low in temp while afloat due to surrounding water keeping boat temperature elevated.
 
I'm sure as he says - other experts will make their comments.

**********************************************

Yep.....good advise.....we all agree though not all duplicated...

get the water out via DRAINS! Not emusification. /forums/images/graemlins/laugh.gif
 
Thanks all, very interesting and, I feel, correct. I'll do some motoring to use up the stock diesel and refill with fresh, untreated and see what happens.

thanks

Brian
 
Best to get rid of it as all those oil water boundaries are havens of refuge for the dreaded bug....much better to have a wee puddle of water in the bottom of the tank /forums/images/graemlins/smile.gif
 
You must log in or register to reply here.

Other threads that may be of interest

Refueler
Strange water accumulation ...
Replies
9
Views
319
Refueler
Refueler

Share this page

Top