Intemittent and drop to zero hints at a broken wire that touches most of the time and opens at just the right conditions.

I had to refurbish the joints of both my rear level sensors and I recommend you do the same (or replace the arms that contain the joints). It's a defective design that will rust solid and will self destruct eventually.

The balls will pull out of the socket you can spin them in a drill to remove the rust and pack the joint with thick grease when you pop back together.

The bolts that hold the sensors are hardware common parts so don't be too concerned about breaking one.

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