Rattle from exhaust gasket

Is this anything I should be concerned about?

https://m.youtube.com/shorts/EG4jHmEMimk

 

From the video, I'd say it's probably leaking exhaust.

By the way, I'm enjoying the documentation of your work so far.

 

I'm no expert, but I would imagine an exhaust gasket giving you the raspberry is not a good thing, and as @backpacker says, you have an exhaust leak.

 

You guys are right. Got to check it out. I don't had a shop vac or a leaf blower, but I a pair or extra hands and a rag. It seems like there are a few muffler sealers on the market if I find there is a problem.

 

Yes, it turned out to be exhaust leak. I asked someone to cover exhaust pipe with a rag, while I was watching for any exhaust leaks. It was fairly easy to find, not so much by sound but by the water escaping through the holes.





Found two leaks. The first one was at the weld site, and the second one at the site I was showing in the first video.

I read somewhere that exhaust leaks after the oxygen sensor don't effect air/fuel ratio. My fuel trims show that I am running slightly rich on both of the banks. -5% at idle to be exact. Not sure if this is what is causing it.



I cleaned out the surface the best I could around with a wire wheel.



After I found out that these carrot looking things were actually studs, I just knocked them out with a hammer. There was nothing holding this assembly in place anyway.


This is what was left of the gasket and two studs.




I separated both parts of the exhaust with two ratchets straps. Just enough to get the gasket out and clean the mating surfaces.





I cleaned out the surfaces with wire brush, screw drivers, and whatever else I could find. Some rust was still left on them, but it was certainly better than it was before.





It looks like someone was either trying to fix the flanges by welding around the bolt holes, or old bolts were welded onto the flange. I cleaned evened out the welds to create a flat surface for large washers. Bolt holes still look good, and the flanges are still in okay condition. The bottom bolt hole is a little worn out, but I don't think it will affect clamping in any way.



M10-1.25 x 35mm Class 10.9 Bolts should fit fine. Based on tightening bolt reference chart, I can torque these to about 60 ft/lbs. According to repair manual, page 2543, all I will need is 35 ft/lbs. If I use two heavy duty washers on both sides and a lock washer, it should do the job. Not sure if loctite will withstand high temperatures.



It seems like my other option is to get one of exhaust split flanges. Exhaust

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My main concern was not the flanges, but the gasket. The surface under the gasket is a bit uneven.

It seems like Fel-Pro answered my question in regards to that:

"Because exhaust system replacement gaskets aren’t installed onto pristine surfaces but onto imperfect surfaces in the repair environment, they must withstand heat and motion as well as compensate for corrosion and warping.

Fel-Pro exhaust system gaskets are designed to effectively seal exhaust system joints and surfaces, especially those sealing surfaces that are no longer perfectly flat and corrosion free.

https://www.felpro.com/technical/tecblogs/felpro-exhaust-system-gaskets-basics.html"

PartSouq point me to OEM part number 90917-06089. The inside diameter of the gasket that I measured is 1-15/16". Fel-Pro product finder points me to the Part Number: 61040 based on OEM part number 90917-06089, which is 1.930 in. Amazon has that gasket for $7.79 with one-day delivery. Ordered and waiting.

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I decided to use J-B Weld 8297 High Heat 500 Degree Epoxy Putty Stick to repair the hole next to the weld. Based on the reviews, it should get the job done.

 

After installing a new gasket and new bolts, exhaust leak still continued.



I also discovered another exhaust leak after the muffler. This would be the their one.



Another poster suggested to use Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker along with the gasket. That was exactly what I needed to completely seal everything.



Exhaust gasket after the muffler was an aftermarket gasket. When I purchased the car, it had a new muffler installed, so I guess a lot of the exhaust components were rusted out after the catalytic converter.

Since the gasket was not OEM, I had to look for one by size. It turned out to be a huge headache. AutoZone only looks up gaskets by year and model of the car. Luckily there Walker Exhaust Flange Gasket 31374. New gasket was installed along with new bolts.

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For the leak around the weld I used J-B Weld 8297 High Heat 500 Degree Epoxy Putty Stick.



After about 300 miles the patch eventually burned out and detached from the exhaust pipe. I cleaned out the area once again and ordered Permatex 80335 Muffler and Tailpipe Sealer.

At this point I only have several options.

• I can either leave that small tiny hole and just forget about it.
• I can weld it, but I am afraid that with ARC welder I will burn a larger hole.
• I can keep trying different tailpipe sealers.

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I also noticed that my muffler began to show signs of corrosion. In one of the videos on exhaust pipe repair someone mentioned that mufflers usually have small drain holes at this location. My muffler did not have one.



After drilling 1/8" drain hole, all that water poured out of the muffler. I can only imagine how long this new muffler would have lasted me if I didn't make the drain hole at that location.

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Most of the exhaust system had been repaired and modified. The plan is to wait for Permatex 80335 Muffler and Tailpipe Sealer and see if it will seal the weld hole. Once that hole is sealed I will paint the areas that I sanded with Rust-Oleum 248904 Automotive High Heat Spray Paint.