“Never lower than 1/4 tank” is not a good thing. You have to occasionally go lower to confirm your siphon jets are functioning and there is zero benefit to the electric pump. Once you are below about 1/3 or 3/8 of a tank there will only be about 5l of fuel in the right side of the tank.

I bought a knock off pump that only lasted 10 months but since it was warranted I replaced with the same and it’s been working ever since. I thought the pump died so I bought a Bosch and discovered it was the fuel level sensor that was whacked and just fixed that (wrote a DIY).

While you have the back seat off, check your siphon jet o-ring since they tend to fail about 140,000 miles

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)