AmazinglySmooth

I recently noticed a high-pitched fan sound in the interior of my E500. Does the Command hardware have a cooling fan? Should I be able to hear it?

Clinton Horn

The blower for the HVAC system is very prone to bearing failure. Squealing is usually more noticeable at lower fan speeds. If you investigate and this proves to be the problem, they can be purchased from parts houses as a BEHR OE replacement. They are under $150 unless the speed controller fails (it can be purchased separately). I don't think the replacement part is an improvement, just stops the noise for a few years. I posted a picture write up for the replacement. Good Luck, I may be completely off track about the source of the problem

Neoii

I've heard this on mine too. It only happened a couple of time last summer. I just wanted to post here so I can find this thread again if it comes up again.