[compressionignition]

Can't stress enough how important this is, had an x5d in my shop last week that was setting fuel pre-supply faults due to a clogged fuel filter.

Having some type of diag tool (autologic, autel, or equivalent) is good as well in order to run the bleed procedure post-filter change. The tool runs the in tank pump for around 2-3 mins, and then prompts you to start the engine and runs the car at 2000ish rpm for 10 minutes. Change filter with a somewhat warm engine to avoid having to let it sit at that high rpm range when cold during bleed procedure. Can also just start vehicle and put something heavyish on the go pedal for a bit as long as you can get it to hold steady. Improper bleed will leave you long cranking for a few starts with air left in the lines.

[Persian Whisperjet]

Originally Posted by compressionignition

Can't stress enough how important this is, had an x5d in my shop last week that was setting fuel pre-supply faults due to a clogged fuel filter.

Having some type of diag tool (autologic, autel, or equivalent) is good as well in order to run the bleed procedure post-filter change. The tool runs the in tank pump for around 2-3 mins, and then prompts you to start the engine and runs the car at 2000ish rpm for 10 minutes. Change filter with a somewhat warm engine to avoid having to let it sit at that high rpm range when cold during bleed procedure. Can also just start vehicle and put something heavyish on the go pedal for a bit as long as you can get it to hold steady. Improper bleed will leave you long cranking for a few starts with air left in the lines.

Very interesting. I did mine last weekend and used the Autel to activate the lift pump for 120 seconds. What is the logic of running the engine for 10 mins?

[compressionignition]

Originally Posted by Persian Whisperjet

Very interesting. I did mine last weekend and used the Autel to activate the lift pump for 120 seconds. What is the logic of running the engine for 10 mins?

Originally Posted by Persian Whisperjet

Very interesting. I did mine last weekend and used the Autel to activate the lift pump for 120 seconds. What is the logic of running the engine for 10 mins?

I can't comment as to the logic of the ten minute run but the main point as I understand is to bleed air from the fuel system after the supply line from the tank is open during fuel filter replacement. If you are using ISTA or any tool capable of running BMW service functions the function listed as "bleeding fuel system" or something along those lines runs the in tank fuel pump for around three minutes and then instructs you to start the vehicle, at which point the service function holds the engine speed at around 2000 rpm and tells you to let it run in this condition for 10 minutes.

[kpm]

Thought I would share this picture of a 335d fuel filter removed after 85,000 kms (53k miles) near twice the BMW recommended change interval.
[IMG]C:\Users\KPM\Pictures\Bmw 335d\Fuel [/IMG][/IMG]
Surprisingly clean with very few particles and no grime in the filter pleats as I have seen previously on this forum. Most of the visible particles are metal filings from the sawcut.
My curiosity was tweaked by my Volvo SUV V8 that consumes 1.5X the volume of fuel versus the M57 yet has is smaller filter with a similar metal cannister design(same manufacturer). The Volvo recommended change interval is 168,000kms(105,000 miles). I dunno...is gas different than diesel fuel to a filter?....is Canadian diesel fuel of different quality?
Yes fuel filters are cheap... but logic does leave the BMW replacement interval in question.

[Nadir Point]

Downstream pressure is the best measure for fuel filter change intervals. Filters filter better the longer they remain in service, right up to the point where they no longer provide the necessary flow rate. The last fuel filter I changed on one of my trucks was because it had a big rust spot where the paint wore off on the bottom. Poor quality fuel can change that interval very quickly.