Thread: External fuel filter

whilst I haven't looked at any options, I'd be interested to see a product on the market to enable fitting up an extra filter easily. Although, like the standard filter I reckon fitting it up under the car is a dumb idea. All's well and good for a normal workshop service, but wouldn't be much fun out in the sticks draining water or changing the filter after getting a bad tank of fuel.

I'm led to believe that the fuel flow is too high to be able to use a separator so a sensor with a readily emptied bowl is the only option. One is already available but expensive to purchase and expensive to fit because the fuel tank has to be lowered, not that that's too hard a job if its almost empty.

Originally Posted by Graeme

I'm led to believe that the fuel flow is too high to be able to use a separator so a sensor with a readily emptied bowl is the only option. One is already available but expensive to purchase and expensive to fit because the fuel tank has to be lowered, not that that's too hard a job if its almost empty.

They use them on Landcruiser 200 diesels and those use more fuel and would have higher flow rates, so for me at least, that does not make sense.

From my quick research, one common element of common rail systems is that manufacturers want to keep the fuel cool. This aids performance. While most kits in common rail diesels offer in bonnet installation, they all would be heating the fuel. This must be bad.

The other issue is flow ... and any reduction in flow will void an engine warranty, from likely any manufacturer. Diesel fuel acts as a cylinder lubricant I think ... starve the fuel flow and hence you void warranty. Since a 30 micron separator is the common size, I presume they do not lower flow ... but 30 micron is too course for a common rail motor I believe.

There are water sensors available and they promise to not alter the flow. They just warn you that there is moisture in the fuel. But putting one in the engine bay would heat the fuel ...

A well researched article (listed following) finishes by recommending a filter ... but from what the article says, its a strange recommendation. The article warns about country farm equipment diesel - don't buy diesel from a station. It also warns about old diesel, and the danger of diesel containers contaminating fuel tank diesel when filling; and it also warns that if there is water or contaminants, the damage happens when the tank gets to its bottom quarter of fuel.

Its seems to me that the best protection for a Disco driver is to add a fuel tank and to not run below a quarter tank, and to change the fuel filter regularly, plus be careful where you fill up. I find the pre filter devises very interesting too ... why not clean the water out before putting it in your tank??

Berrima have good advice about buying fuel: "Good filtration starts before you stop to fill up. Buy fuel from a known brand station, try and stick with one brand as much as possible, keep you receipts." If the fuel has water in it, then buying from just one supplier must make a claim much more straightforward. This also is another reason why a secondary tank is a benefit IMO. I have not wanted to put in a secondary tank ...

It is interesting too, that a net search could not find a pre water separation filter for a Ford Territory diesel, which uses the 2.7 litre land rover motor, in what I presume would be a fairly high selling vehicle (although the diesel option did cost another $3,500). All AWD Territory from 2011 on had the diesel.

The article I found most useful is here, but I think the conclusion to fit a filter does not accord with what the article reports:
https://practicalmotoring.com.au/car...ngine-at-risk/

you can have flow and small micro filtration size, but you need to increase the physical size of the filter to do it. The other factor in filters as well is the beta ratio - in essence thats the efficency of the filter, no point having a 5 micron filter that lets 80% of 5 micron particles through

This is a pic of a 2006 (I think ) D3 with a extra filter added. The forum member who emailed me this told me he never had any issues with the flow rate. He said the water senser had an idiot light installed inside the car for when it was sensing water.


Just needs to be shrouded correctly , sadly its the earlier type filter than my 2008 but it can be done.


Cheers Ean