feedback?! - Benzworld.org

rfaquino · 12-23-2003, 03:49 PM

hi. i'm new to the group. i just bought a used C280 Sport and i love it. only thing is, i noticed that whenever i slow down from high speed (between 60-80 mph) i hear a sound much like the feedback of a microphone when its set too close to a speaker. i tried isolating the situation like if it only happens when i step on the brakes or it only happens when i reach a certain lower speed but to no avail. it just happens. any idea what this is? this is my first mb so i have no idea what this could be. . .

moebiusgold · 12-23-2003, 08:31 PM

Are you all the way out of the gas, partway, on the brakes, hard on the brakes? Any other vibrations or? Allways the same hot or cold, good pavement or old, Need more info or a ride. You could record a MP3 and post it. That would be a real help.[:)]

DuncanM · 12-24-2003, 09:08 AM

Interestingly enough I had the same thing happen the other day on my C43. I was on the parkway going about 70 and traffic was stopping infront of me. I applied the brakes lightly as I was pretty far from the slowdown. I heard the sound you described and turned down the radio as I thought that was the source but the sound persisted. Once I got <10mph I let the brakes off altogether and the sound stopped. It hasn't done it again. The car was dry and the road was dry. It sounded like it was coming from the rear of the car but it did not sound like anything I've heard brakes do.

rfaquino · 12-24-2003, 11:40 AM

yeah, i thought it was the brakes but i don't think so coz it happens even if i just take my foot off the accelerator and not tap the brakes at all. i even turned the radio off thinking the sound system may be grounded but nope. it still does it. hmmm . . .

rfaquino · 12-28-2003, 09:06 PM

ok, i took the car out for a drive all day today and as i was parking into my garage, i revved the engine to 3000 rpm. it then made that oh so familiar mecrophone-feedback-sounding sound as the needle went down to 1000 rpm. so there i was thinking all this was speed related when all that time it was not. i'm still dumbfounded as to what it is though. any help would be appreciated. thanks!

moebiusgold · 12-28-2003, 09:11 PM

So have someone do it while you are standing outside. Do it till you can figure out where it is coming from. When muffler baffels brake, the exhaust can make wierd noises. Good luck[:)]