Fix leaking manifold to y-pipe with furnace cement

[CDW6212R]

Okay, more suggestions; cut it all out and fabricate new pipes, leaving out the ball connections, weld in v-band clamp/flanges. Those never leak and are easy to R&R.

 

[J$hort]

I've done the 2 piece, split flange trick on my Ex and many others and it works great. Got many miles out of it until I chopped Y pipe out as it was toast. Installed new Y and fabricated my own flange and gasket into a 3" exhaust.

 

[masospaghetti]

Thanks everyone for the suggestions.

I've tried the copper RTV as well as carefully retorquing / positioning and the ticking has reduced, but I can still hear it.

I've tried using a rubber hose to the ear to try and confirm the location of the leak but can't hear anything, tried with the engine running and with a shop vac in the tailpipe (pressurizing the exhaust with the engine off)*.

Sounds like I need to either try those split flanges or get a replacement y-pipe. Luckily even a y-pipe isn't super expensive (about $80-90 from Walker).

* This is a nice trick that revealed a leak between the cats and the muffler, and a minor leak between the y-pipe and the cat.

 

[96eb96]

@masospaghetti

LINK TO PERMATEX ULTRA COPPER RTV:

Permatex® Ultra Copper® Maximum Temperature RTV Silicone Gasket Maker

OEM specified. For high operating temperatures common in 4-cylinder, turbocharged or high-performance engines. The most advanced, high temp RTV silicone gasket available. Sensor-safe, low odor, noncorrosive. Superior adhesion. Three times more oil resistant than conventional silicones; eight...

www.permatex.com

Main Points from the LINK:

" Temperature range -65°F to 700°F (-54°C to 371°C) "

" Suggested Applications: Exhaust manifolds/headers, turbo charger applications, and slip-fit exhaust parts."

They have a new product called Optimum Grey. Also goes up to 700, says it is for exhaust headers. I used it for my upper intake corners to seal things up, probably overkill but it is a good product:

FAQs

Knowledge Base.

www.permatex.com

 

[spinnn]

Sounds promising! I will try these. Thanks for the suggestion!

Makes me wonder if the solution could be even simpler - like taking a thin sheet of aluminum and using that as a gasket, could make it from a soft drink can.

Might cause galvanic corrosion, esp. in the presence of acids and moisture that exist in the vehicle exhaust

Galvanic corrosion - Wikipedia

en.wikipedia.org

 

[410Fortune]

or you can just use the Chevy exhaust gasket that is made for this situation!

 

[masospaghetti]

or you can just use the Chevy exhaust gasket that is made for this situation!

I ordered the gasket you linked, and it was way too big! Also I ordered two, and they were two different sizes. Maybe I just got a bad vendor.

 

[410Fortune]

dang!! I did a quick google search and pointed to the one I thought would work
What I do is go to the auto parts store and look at their selection of exhaust O ring gaskets, then pick from the stack
I will see if I can get an accurate part number for you I should still have two of these downstairs
Sorry for the confusion! The one you need is like 2 in diameter

 

[masospaghetti]

I finally am shelling out $ for an automotive shop smoke generator...I have been wanting one for awhile, and hopefully that will make it easy to spot exhaust leaks. I imagine it will be useful for finding intake leaks and air/weatherstrip leaks too.

 

[masospaghetti]

So I did find a minor leak on the passenger y-pipe using the smoke machine, which went away when I loosened and tightened it back up. However I still have the noise.

What could cause a noise similar to an exhaust tick, that wasn't actually an exhaust leak? I can only hear it under load and its more pronounced with the windows open.

I thought maybe valvetrain but I thought valve noise would not be dependent on engine load?

 

[CDW6212R]

The EGR pipe with a crack in it will make that sound, but also check out the cats, the shields on them can rattle with odd sounds.

 

[410Fortune]

I am glad this came back up
I finally found the correct gasket for this fix


60517

 

[fast_dave]

@masospaghetti

Try to go to an area that is somewhat silent and has a long length of wall that you can drive next to (like the backside of a strip mall or grocery store), opposing window down each pass, and drive each each direction.

You should be able to figure out which side it's on - hope I'm making myself clear but I think you get the idea

Over the years I've narrowed down strange noises (that I didn't hear otherwise) just by accident when driving next to "K Rail" with my widows down.