JGaulard
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- Apr 12, 2019
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- #1
Last year, I began noticing an exhaust leak coming from one of the dual pipes beneath the passenger side of my 2009 BMW 328xi. I jacked the car and inspected the exhaust. I noticed that all four flange bolts were rusted and I felt and heard air escaping from between one flange. To remedy this, I removed the exhaust pipe hanger that sits about two feet behind the flanges and then shook the offending flange loose. Then I used a sawzall to cut the rusted bolts from that flange. The other flange didn't seem to be leaking, so I left it alone.
After I cut the bolts, I installed a new flange gasket and then installed a 2-2 1/2 inch Surebilt split flange. The repair seemed to work just fine.
Fast-forward a few months and my exhaust began leaking again, this time, from the other flange. Apparently, those remaining bolts rusted enough to loosen the seal and, again, exhaust was escaping to make that horrible noise leaky exhausts make. Take a look at the photo I took of the rusty bolt and flange. As you can see, I already cut the tip of the bolt off.
To repair this leak, I thought I'd be able to simply sneak a metal sawzall blade between the flanges and cut the other bolt. Because I didn't have enough room under the car, I wasn't able to do that. I was forced to remove my prior split flange repair to access the bolt. When I had the room, I cut both remaining bolts. Then, I added a new gasket to the remaining flange and used another split flange to repair the leak. Here's a photo of that.
To avoid future rust, I used zinc-plated grade 8 bolts, nuts, and washers. I also used some Locktite to ensure the nuts wouldn't work loose. These split flanges seemed to do the trick because the car is quiet again.
Questions? Does your BMW leak exhaust? If so, ask away and I'll try to help.
After I cut the bolts, I installed a new flange gasket and then installed a 2-2 1/2 inch Surebilt split flange. The repair seemed to work just fine.
Fast-forward a few months and my exhaust began leaking again, this time, from the other flange. Apparently, those remaining bolts rusted enough to loosen the seal and, again, exhaust was escaping to make that horrible noise leaky exhausts make. Take a look at the photo I took of the rusty bolt and flange. As you can see, I already cut the tip of the bolt off.
To repair this leak, I thought I'd be able to simply sneak a metal sawzall blade between the flanges and cut the other bolt. Because I didn't have enough room under the car, I wasn't able to do that. I was forced to remove my prior split flange repair to access the bolt. When I had the room, I cut both remaining bolts. Then, I added a new gasket to the remaining flange and used another split flange to repair the leak. Here's a photo of that.
To avoid future rust, I used zinc-plated grade 8 bolts, nuts, and washers. I also used some Locktite to ensure the nuts wouldn't work loose. These split flanges seemed to do the trick because the car is quiet again.
Questions? Does your BMW leak exhaust? If so, ask away and I'll try to help.
