Oh boy, I discovered on my new SDL that there was a big flaw in the exhaust pipe that had been covered up with some sort of wired on sheath. I was getting exhaust smell in the car and could see it emanating from the flex area under the hood. The next morning, I jacked it up and, oh yes, there it is. A rusted spot big enough to stick fingers in.

As bizarre luck would have it, I still have the entire exhaust pipe with mufflers from my '81 300SD, now sent to the great dismantler in the sky. I had removed it at one point and forget to send it on. The flex joint and surrounding pipe, perhaps even the flange going to the manifold looks identical to that on my 300SD. You can see superficial rust from the pics but it's way solid compared to the rusting original.

I had done an air leak test with the blow side of one of my cheapo Home Depot shop vacs, the $29.95 Stinger - I have 3, I saved the first two after they broke and when the 3rd broke discovered it was only a bad switch on all 3. Moral to that story, don't throw that stuff away, 1/10 of its life span is defined by the original switch.

One I use only for wet vac, no dust therein so I put it on one end, duct taped it to mostly seal and found major leakage under the sheath, which I, of course, expected. But leaking nowhere else.

I then did the same with the 300SD exhaust pipe. Putting soapy water on the flex part, I got copious bubbles. Wasn't surprised by that, would be real hard to make that air tight.

I might just weld it on for now, but I might be a fool not to get a new unit. Last night I found flex joints - I swear - in the Pelican Parts catalog, I should have saved the link because I can't find it now.

I found something similar on another site, must be a competitor because it won't allow the link to post. No sweat, I'd rather buy it from Pelican. Looked like this:



Probably shouldn't be stainless, harder to weld.

Question being, some leakage is likely acceptable at the flex joint, no? It is making bubbles but the stream of air making it past the wadded up paper and duct tape at the end, this on the other side of the mufflers, is way stronger than what I'm feeling blow out from the flex joint.

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Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K