I didn't know the SD's also had self healing properties. That was usually relegated to the W123
You'd be surprised at what that air cleaner can do! The wagon's air cleaner is broken on the rear arm and it shakes noticeably. The sedan's air cleaner bracket is intact. It may only be a few pounds heavy but it's on top of the engine and when it vibrates, it has "good leverage" enough to shake the car (I suppose)...?