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J Ralphs Just got MTs
Joined: 04 Nov 2006 Odometer: 187
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Posted: Sat Dec 29, 2012 7:43 pm Post subject: Why does my fuel filter get blocked on 100% bio
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I am aware of a few cars running on high quality 100% bio for a few years. Most have a problem with fuel filter blocking up. A Peugeot 306 with the 2L common rail engine has never had a problem in 2 years. Two 300tdi Defenders block up in winter about every 3 weeks, but rarely block up in summer. A Renault Laguna 1.9DCi engine is the worst and blocks up in winter every 2 weeks. It also blocks up in Summer every 5 or 6 weeks.
The bio is made from WVO with no palm oil. Although I can't be certain, I don't think there are any animal fats. It is filtered to 5 microns and passes a 27/3 test with no sign of soap. It is dosed generously with Coldflow 402 (I know 402 is really for palm oil and that 350 could be use, but 402 is really belt and braces I think). Cetane improver from Chemiphase is also added.
Any idea what might be causing the fuel filters to block up so often ?
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Alex90 Articulating
Joined: 19 Apr 2010 Odometer: 861 Location: preston, Lancashire
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Posted: Sat Dec 29, 2012 11:57 pm Post subject:
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When you say block up does the fuel filter get full of waxy gunge or dirt and debris from the fuel tank?
Does the pug 306 have a heated fuel filter head? Some frenchies do which might explain why it doesn't have a problem.
The Renault may have a finer filter on it than the defenders with it being common rail which is why it may block up more often than the others. I have heard from a friend that bio made from veg oil that isn't rapeseed or sunflower oil can wax up when the temperature starts to drop but I've never tried bio myself. I dont trust the producers of it so I just use SVO in my truck.
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J Ralphs Just got MTs
Joined: 04 Nov 2006 Odometer: 187
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Posted: Sun Dec 30, 2012 12:28 pm Post subject:
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Thanks for the thoughts Alex. When the filters block up, there is no sign of dirt, debris or wax. They appear perfectly normal but just a bit slimy.
The Peugeot does have a heated route for the fuel but, oddly, it is fitted after the fuel filter.
To the best of my knowledge, all bio made from vegetable oil will tend to wax when the temperature drops. There are some interesting graphs on the Chemiphase web site which show the extent to which different oils are affected. The simple solution is just to add something to stop the waxing. I've had no waxing even when temperatures have been down to -12 centigrade over a few days.
Having run the Laguna for 2 years on bio, I finally gave up about a year ago and took the filter out. So, no fuel filter. I reckon, that having run for two years, the bio should have cleaned out the system sufficient to not need a filter - particularly as I know how carefully the bio is produced. No problems since. I even had the injectors tested when I suspected a problem, but they were all firing perfectly. The fuel filter was also taken out of one of the 300Tdi Defenders a year ago, and that has run faultlessly since with high annual mileage.
The thing that puzzles me is that the spec for the Laguna fuel filter is 10 microns. By having the bio filtered in production to 5 microns, I would have thought that it should pass through the Laguna 10 micron filter with no problems. Clearly there is a problem, but I don't know why.
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parrotveasey81 Mud Obsessed
Joined: 13 Feb 2009 Odometer: 7480 Location: bradford on avon (wiltshire)
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Posted: Sun Dec 30, 2012 3:35 pm Post subject:
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J Ralphs wrote: |
The thing that puzzles me is that the spec for the Laguna fuel filter is 10 microns. By having the bio filtered in production to 5 microns, I would have thought that it should pass through the Laguna 10 micron filter with no problems. Clearly there is a problem, but I don't know why. |
depends on hows it been filtered
if its filtered hot then any fats in there will have melted and will go through the filter but when they cool down and mecome more solid again then they wont
put some bio in a empty coke bottle and leave it in the shed to see if it starts to separate or go cloudy over the next few weeks
__________________________________ http://www.bloodredoffroad.com/
Angry parrot fabrications,check me out on Facebook |
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J Ralphs Just got MTs
Joined: 04 Nov 2006 Odometer: 187
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Posted: Sun Dec 30, 2012 4:06 pm Post subject:
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Good suggestion. Yes, the bio is often filtered hot. I'll let you know what happens.
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parrotveasey81 Mud Obsessed
Joined: 13 Feb 2009 Odometer: 7480 Location: bradford on avon (wiltshire)
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Posted: Sun Dec 30, 2012 4:41 pm Post subject:
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J Ralphs wrote: | Yes, the bio is often filtered hot. |
imo thats your problem
__________________________________ http://www.bloodredoffroad.com/
Angry parrot fabrications,check me out on Facebook |
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J Ralphs Just got MTs
Joined: 04 Nov 2006 Odometer: 187
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Posted: Sun Jan 06, 2013 10:55 am Post subject:
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It looks like you were right. I have just looked at two samples of bio that have been sitting in the workshop for a few days. The old sample was taken from the process when I pumped out hot. The new sample was from when I pumped out cold. Old is cloudy and impossible to see through. New is as clear as whisky. As I've been storing the bio in an IBC, I had not realised how cloudy it was.
Many thanks for your help and advice.
John
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J Ralphs Just got MTs
Joined: 04 Nov 2006 Odometer: 187
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Posted: Thu Jan 10, 2013 11:05 pm Post subject:
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There has been a further development which I don't understand. The two sample bottles of fuel stood side by side for three days. Hot pump-out was cloudy. Cold pump-out was clear. After 3 days, the previously clear cold pump-out started to become cloudy. After 6 days, both bottles looked the same. Cloudy. Both bottles were uncapped but inside a workshop. The outside temperature has dropped over this period from 7 degrees to between 1 and 2 degrees. Both samples have been treated at the same dosage rate with Coldflow.
Any ideas please why the previously-clear cold pumped sample should have gone cloudy ?
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parrotveasey81 Mud Obsessed
Joined: 13 Feb 2009 Odometer: 7480 Location: bradford on avon (wiltshire)
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Posted: Fri Jan 11, 2013 8:08 am Post subject:
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might just be due to the cold temps,take the cold one and put it in the house in the worm for a few days to see if it clears
__________________________________ http://www.bloodredoffroad.com/
Angry parrot fabrications,check me out on Facebook |
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