WHen you start to feel some hesitation or poor
idle or even poor gas consumption (low MPG), it could be
due to dirty Mass Air Flow Sensors (MAFS). MAFS are considered consumables and
should be replaced approx 60k to 80k miles. If you need replacement MAFS, please
check out BMW Mass Air Flow Sensor Page. But intermediately, you can clean the MAFS to keep it
in tip top conditions, you can do it in intervals of 15k miles or 20k miles.
Cleaning the MAFS are very simple. Take a look at this general guideline and see
that it only takes about 15 mins. This procedure was done on a 2007 BMW 550i but
other models should be in general the same procedure.
Locate your MAFS under the hood, its very
simple to find, remove the clips that cover the sensor (for some models, it
might be easlier to remove the entire unit)
Using the appropriate Torx bit (some BMW use
the 5 or 6 star, some are security torx and some are regular torx), so check
which one you have prior to removal
Once the MAFS is removed from the housing,
disconnect the MAFS from the wire hardness, show in the arrows above.
Use a MAFS cleaner (you can pick this up at
your local auto parts store, we dont stock as we cannot ship this item) and
follow the instruction on the can, its pretty simple. Just make sure that its
fully dry before reinstalling it back into the housing
Once cleaned, putting it back is as simple as
removing it, just follow the process in reverse and you are all set, you will
now enjoy a smoother idle, better acceleration, and more to original conditions!