Originally Posted by vtmbz

I had a disasterous squealing on my 190d that I was convinced whas the a/c compressor. I drove it for weeks without the ac until I discovered it was actually the auxillary vacuum pump under the rear seat that was failed. It had a slow leak, and would recharge at random, causing a loud bushing failure to reveal itself. The point being that I jumped to a conclusion, and relocated the noise to suit. Your noise may not be engine or running gear related, especially given the long list of new parts.