There is a sensor on my 318Ti's intake manifold that is humming when the ignition key is turned on. I have attached a picture of the sensor. I was wondering first, what is this sensor and second is the humming normal?
I am also getting a check engine light with code 50 (secondary air control) from Table 07 in my Peake Reasearch code book. The car is also not running so good, it feels down on power.
Do you know if the secondary air check valve (the component on the forward side of the valve cover) would cause the "secondary air control" code I am getting?
From what I've read it only works during engine start for a times interval for emission purposes. I'm wondering if the secondary air check valve has failed open and exhaust gases from the exhaust manifold are flowing backwards through the secondary air check valve causing the performance problem I am experiancing?
I thought about just replacing the secondary air check valve and taking my chances but at almost $300 and having to buy the $70 solenoid valve that it is plumbed to is just too risky.
There is a pretty good DIY on removing the IAC and cleaning it. It involves brake cleaner and q-tips, I noticed a differance in the idle. It smoothed out quite a bit.
This thing is humming 
Linear Mode
