My exhaust has been getting louder and louder with every ride. More pops, and occasional LOUD backfires. On Saturday night I took it on a tuning ride, getting ready for ECC, and I could not hear what I was listening for as the stupid exhaust kept going pop-pop pop pop when ever I was off throttle but the car was moving. Add a little gas, and sometimes I get a BANG!

So I put the car in the air. I know that I am going to see, but I am surprised just how bad the sealant I put on the pipes last year have failed.

The guys at aircooled.net had suggested using high temp RTV on the slip fit collector to seal it up. Thats what the red goop was. I put a big bead around the pipe and slipped it in. All the goop that was smushed out I pushed back into the seam with my finger. It worked for a little while, but the popping started quickly. Quiet at first, and then louder and louder.

In the following pics, you can see the cracks and sooty jets where it leaked anyway.


This one was my prime offender:


So, mad, I pulled off the rear of the exhaust from the collector back. The goop made it hard to remove, but a few gentle taps with a rubber mallet did the trick.

This is the collector configuration I am dealing with:

My first thought was to weld it all together, but the way the pipes are, I would never be able to weld the inside of the fourth pipe, and I would be right back at square 1.

ScottyB and Rich Towle have both said to put a flange on it. This is beyond my skill level. Scott could do it over the winter, but that means my car is out for ECC, which will annoy me greatly. But I am not going to drive the car for almost 4 hours if it is popping and backfiring all the way there and back and through the AX course either.

Tomorrow I am going to find a local exhaust shop and take the rear end of my system there. Show them the issue, talk about the flanging idea, and ask if there would be any way to get the car back by the Friday of ECC. I would have to put the back on and take them the car, obviously, if I had any hopes of it fitting right.

Is this a lost cause? Am I doomed to be driving my Subaru to Cumberland 2 weeks from now?

Zach

Zach, what about welding 4 nuts to each side and using all thread to pull the 2 halfs together?

if that doesn't work, there is always duct tape..

Zach there is a product that seals mufflers and pipes that can be found at your local FLAPS in the section with exhaust clamps. Some of the local shops use that to help the pipes seal.

Has that now, actually, though they are pulled tight with springs and not nuts.
What I need is a gasketed flange that I can bolt together to keep it from leaking.

I think for the time being, just to get to ECC and back, I am going to re-goop the pipes and reassemble. That should shut it up through Cumberland and back, I hope. Once ECC is past, I intend to either get a different exhaust system or get this one modified and sealed.

Zach

Could you use one of those exhaust pipe expanders I see at FLAPS to open up the tubes running in to the collector just a bit to get a better fit? Did you notice if it was leaking on the inboard side of the pipes? Slip fits rely on heat to cause the pipes to expand to seal . . . I'm wondering if the collector is in enough flow when you are driving that the outside cools enough to prevent the heat induced seal. Maybe try re-gooping and wrapping the assembly in header wrap to keep the heat in. Definitely not a permanent solution but might get you to the ECC pop free.

Or try muffler cement/furnace cement.


-Chris

Try talking with type47, I think he has a header on his Orange car, may have some ideas on how his seals up.

I'll be out of town this weekend and only have exhausts that work with heat exchangers so my parts wouldn't be of much help.

Best of luck.

PS: I just got an exhaust leak on my DD today...must be some kind of epidemic around here...

Chris, you knwo I was thinking about one of those expanders myself last night as I was falling asleep. Thanks for bringing it back into focus.

Zach

would it be too much to temporarily go back to stock? i have a pair 2.0 stainless headers that i've "borrowed" from Herb. find a 2.0 bracket and muffler and you're ready to go.

I wonder about these projects before events - I started replacing the vacuum hoses last night. wonder what troubles that may turn up!

Why don't you just drive the Westphalia?

Okay, I did not get an expander. Or the oil filter I needed to change the oil in my scoob. That will have to happen tomorrow.

I did get a product called "exhaust weld" that says it does what I need it to do.

My only fear is that I am going to do this, and my exhaust is going to become a solid system, to the point that flanging it - which would be a great solution that allows pipes to be put on and taken off as needed - may not be an option. Which would mean I have exactly 1 chance to get it right.

So, tonight I'll start cleaning parts.

Oh, I also bought a new muffler to weld in. 23" muffler to replace the 12" turbo muffler. And I bought shielding gas and Mig wire. No more Flux core for me, time to learn something new.

Zach

Exhaust is back on the car.

It is sealed with the "Exhaust Weld" epoxy, so for better or worse, the exhaust is solid now. The instructions say to let it dry overnight before running the car, so I will take it for a test drive tomorrow.

I did not get the new muffler on. I did not feel comfortable with the (real) MIG welding. It was different enough from flux core welding that I feel the need to practice more. Wire speed needs to be faster - but that may be due to the thinner wire. The result is, though, that my technique is off and I need to learn this new variation. Also, I am having a bitch of a time seeing what I am working on due to the larger tip.

I ended up getting an 18inch muffler. Its an OE item for GM V-8s of the late 70s and 80s, so it should be much quieter and still flow fine for my little 4. Putting that on is going to be a winter project though. No time for it right now before ECC.

Zach