This isn't really specific to a 580 SL, but I have a rain cap on the exhaust pipe. Is there a way to quiet the cap down when the engine is running so the vibration of the engine doesn't make it rattle? Thin rubber or tape?
Is the noise caused from the rain-cap opening and closing ? Or from the hinge on it vibrating. If it is the hinge a new rain-cap should eliminate the noise. It is quite normal for them to flap up and down at idle or slow engine speeds.
It's the hinge part and not the flap. I bought a new one thinking it would fix the problem, but it's metal-on-metal, so it vibrates just the same as the old one.
Try to find a different brand/mfr. It should net be making noise until it wears out. Is there any way you could tighten the hinge ?
Check low idle speed, it should be about 1100 rpms.
Ditch the flapper and put a 90 on it. No noise.
Good advise Deertracks. I hadn't thought of a 90 on it. I wouldn't want to use one here in Illinois though. It is quite normal to have rain, sleet and snow being blown horizontally. Sometimes all in the same day. I used an empty soup can for quite a long time. It was amazing how far it would sail when I would forget to take it off the stack before stating the engine. I finally bought a flapper to replace it.
Higher quality flap would be my suggestion.
A OEM pipe has a fairly long 45 on it and we have never had a problem with weather related engine problems. the muffler does not fasten to the stack anyway so water running down the pipe would probably not enter the engine. The muffler top pipe just sticks up into the pipe which is fastened to the tilt hood and the pipe tilts as well. An OEM pipe will solve your difficulties. Mel
Somewhere I ran across a thermostatic flapper, opened mechanically as it heated, closed tight when cold, that would probably help if you could find one.
It's probably not an OEM pipe, as the pipe doesn't have any bends in it. I've tried 3 flappers and they're all the same design and made the same rattling noise. I may look into that.
I do have to correct one error I made, the pipe does indeed clamp to the muffler and does not raise with the hood as some models did, you can go to the Case CE parts lookup and see the pipes as installed by Case OEM.
Turn the radio up. Earplugs?