Fix leaking manifold to y-pipe with furnace cement | Page 2 | Ford Explorer Forums - Serious Explorations

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Fix leaking manifold to y-pipe with furnace cement

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.

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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.




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.



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:


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


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

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.

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

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.

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?

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.

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





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 :cool:

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.