[Ihdihd]

I recently took over an i7 lease with a few thousand miles, and thought it would be best practice to replace the cabin air filter. Who knows what the last guy did in the car to despite it looking completely new.

After a bit of research here, I discovered that there is a nano filter available that filters beyond our traditional filter. I ordered one from the bmw dealership and it looked quite similar to the exiting one.

The install was an absolute nightmare- almost 2 hours (vs. 15 minutes for the hardest filter I’ve replaced in the past). Between the difficulty of install and the expectation vs reality of the difficulty, I would have sooner rather rebuilt the engine on a gas car than do that install again.

There are some instructions I tracked down (attached). I will say that at every step of the way there was a laughably difficult thing to do:

1. Removing trim - once the two clips are rotated and out of the way, you have to pull the trim out of its track on the left side of the well. Then I clip the entire light assembly out of the trim (knock it in) instead of pulling the wire harness. After that you have to remove the vent tube- easiest part, then remove the hose on the left. The hose is attached via a small hole latch- simply lift the rubber a bit from top and bottom and it will unlatch, then you can hand pull it.

2. Unscrewing the tiny metal screws required a torx T15 bit, and I had to switch between a straight long driver and a smaller 90 degree wrench due to each screen being in an impossible position to reach. There are 6 screws in total to remove (not 5 as in image). And they are all there and the only way to see them is to contort your body so your head is deep inside the well. The farthest screw on the upper left was the biggest pita - completely inaccessible with the perfect size, perfect shape ratchet. You need a lot of patience because one wrong move and it will drop into the abyss behind the carpet and it’s gone.

3. Once the screws are out, unclipping the right side of the filter cover is a nightmare - again a perfect sized perfect shape flathead screwdriver is needed to unlatch it, essentially in the blind.

4. Closing everything up is easier than taking it out, but again- putting the final trim covers back in their tracks was a real PITA. Had I not already bought it and committed, I would have happily let the sealer do it. It would have been the best $500 I spent.

In sum- don’t do it unless you love pain. I don’t know why BMW designed this massive land yacht and decided to put 80% of their systems in the passenger footwell inaccessible except to contouring circus performers with tiny hands.

What would have made it better- 1) a super low profile right angle ratchet with wobble bit; 2) a good mirror like the dentist ones; 3) much better battery flood light in the footwell; 4) printed instructions.

I didn’t notice any difference so far, but I’m sure it’s better than a 2,500 mile old filter…

Here are the parts:
64-11-5-A54-7D8 Filter Element $145

And attached are the instructions. Follow them religiously.