Where is the fuel filter on a x5 diesel - 2005 BMW X5

I am leaning toward a fuel problem. Loss of mid-range power, misses or pops, and backfires are indicators of not having enough fuel. I am guessing some of your injectors are still not fully functioning.

Nope it is not a coincidence as the 2011 x5 is not rated for that bio diesel and has probably damaged the fuel system

is it a diesel bmw x5 if so it is your fuel line,and if it is not a deisel then has the be something other then dieisel

If your fuel consumption is normal I don't think you have any worries.

I would say that having checked the fuel and air filters that theres a stong possibillity the turbos not kicking in, dont forget an x5 is a big lump and without a turbo the result would be as you describe. regards KSK

Changing the fuel filter on an early X5 3.0 diesel is dead easy even for a novice
Pop the bonnet
The Fuel Filter is a round soft drink can size unit. Look for the main black plastic air inlet thing leading to the top left of engine bay (on your right as you face the engine) leads to a mini radiator looking think which is a fuel cooler, the fuel filter is the silver can thing right behind that..
Disconnect with a phillips head screw driver the two flexible fuel leads, unclip with your thumb and forefinger the plastic sensor,
loosen with an Allen/Hex key the side clamp and slide vertically up and out. The hex key needed is one of the larger common sizes in any hex key set from any spare parts store. Reverse the above to fit the new one. turn key On for a few moments while the pump charges the filter, check for leaks and you are away.
Its easy and should be done every 3 or 4 oil filter changes

I need also,told by main agent filter is adjacent to passenger ns
sill,there is a cover there,looks like the big one over the underside?
will post after I do the job KJ

bmw 2005 55reg diesel onboard computer says fuel inject.system but starts and drives

yes fuel filter is installed and must be changed every 10 000 km like clock work but it is a lovely car and you will have lots of fun

Your description reminds me of several vehicles I have encountered in my career that behaved in a similar way. They had all had body repairs at some previous time near the fuel filler and all gained something in the fuel tank - cloth or worse a plastic bag that was used for masking purposes.
One van was fitted with a high pressure pump by the dealer at a massive cost only to discover there was no improvement - they later removed a plastic bag from the fuel tank.

Water in the tank is another possibility. If there is a strainer in the tank it will be typically too fine for water to pass through.

If there is no obvious faults I suggest you ensure there is nothing in the tank but good clean fuel and the pipework is good including the breather system.