The next project on my 93 240 is to find the source of a buzz which sounds like it is originating from behind the dash. But, I'm not 100% positive that's where is coming from. So before I pull out the whole dash trying to find it, thought I'd check with this group first. This buzz sound occurs when accelerating moderate to hard. Under gentle acceleration, no buzz is heard. More specifically, it can be heard immediately after each upshift. After about a second or two it disappears, then returns at the next shift point. Sounds like a sheet metal buzz, like something is slightly loose. Or maybe a cable buzzing against the firewall? If you've had the same problem in your 240 and have found the source of the buzz, I'd sure be interested in knowing what you discovered before I tear into the dash on this car. I've also considered that it might be some sheet metal touching somewhere on the exhaust system. Maybe the sound is telescoping forward so that it only sounds like it is coming from behind the dash or under the hood. Any ideas????