This is from a w123 240d that has sat outside since at least 2008. During re-animation all fluids and filters (amonst lots of other stuff) were changed - except the fuel. The tank was full to the brim, so we were slightly optimistic it might have survived, even though the fuel was nearly black (with a reddish hue). A can of diesel biocide was added, as algae/ diesel pest was not unlikely.
After 250km the first signs of loss of power could be observed (running uphill at Autobahn speeds). Power slowly deteriorated. A couple hundred kms later, driveability was severely impaired; immediately before the filter change, the car was struggling to maintain city speeds and would only be able to go with the flow of traffic in the flats - any incline, such as an overpass, would have her lose even more speed.
Both prefilter and main filter were changed after ~850km.
The pre-filter was completely plugged - for a short video see here.
After changing both filters, the car regained it's top speed of 155km/h (confirmed by GPS).
The red stuff may look like rust, but it is very smooth to the touch. There is no grainy structure, nothing hard or sharp, as I would expect from rust. This is - at least predominantly - organic. (It may well be that the red colour comes from very small rust particles - as there was water in the fuel ("eyelets" could easily be observed when emptying the filters, just like fat swimming on a hearty soup...).
Main filter may possibly have been able to go longer. I am currently wicking the filter element dry to hopefully get a better impression of the paper.
Note that the red slime is to be found also on the clean side of the filter, albeit less thick.
A "new" tank is waiting at a friend's place, but it will probably be spring until we can install it. Given that the slime has made it past the filter element, I shall surely purge the fuel system once I got the new tank and have run a tankful or two through the engine.
Finally: the pictures!
After 250km the first signs of loss of power could be observed (running uphill at Autobahn speeds). Power slowly deteriorated. A couple hundred kms later, driveability was severely impaired; immediately before the filter change, the car was struggling to maintain city speeds and would only be able to go with the flow of traffic in the flats - any incline, such as an overpass, would have her lose even more speed.
Both prefilter and main filter were changed after ~850km.
The pre-filter was completely plugged - for a short video see here.
After changing both filters, the car regained it's top speed of 155km/h (confirmed by GPS).
The red stuff may look like rust, but it is very smooth to the touch. There is no grainy structure, nothing hard or sharp, as I would expect from rust. This is - at least predominantly - organic. (It may well be that the red colour comes from very small rust particles - as there was water in the fuel ("eyelets" could easily be observed when emptying the filters, just like fat swimming on a hearty soup...).
Main filter may possibly have been able to go longer. I am currently wicking the filter element dry to hopefully get a better impression of the paper.
Note that the red slime is to be found also on the clean side of the filter, albeit less thick.
A "new" tank is waiting at a friend's place, but it will probably be spring until we can install it. Given that the slime has made it past the filter element, I shall surely purge the fuel system once I got the new tank and have run a tankful or two through the engine.
Finally: the pictures!
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