Sorry if anyone has been waiting for breast augmentation but I think I have slowed up the silicone supply by my attempts to qui ten that incessant and embarrassing rattle. Got underneath and started injection if silicon between the shields through holes already provided. I think half a cartridge fixed it. I broke one gun .

That's a really good idea!! The retaining bolts on mine are seized solid. What kind of silicon did you use ?

keep a close watch on that..  Exhaust pipe temp can get pretty close if not over the operating temp of silicon.

Might be a good safety tip there Dave, thanks. I used roof and gutter silicone. Previously ( and I mean over 30 years previously) I used glazing silicone on exhausts before the automotive industry seamed to have caught on. Yet to have any troubles

 

I tell you what though, the noise,vibration and harshness level has dropped significantly. Very pleased with the result so far.

 

Yes, the holes I filled would ideally be air cooling vents for the rattlers with seized nuts n bolts. Might not have used my noggin totally in the approach. I did see some pale smoke drift out while stopped at traffic lights after , but at least no flippin' rattle

I think this method earns a " don't try this at home boys and girls" tag. It is still smoking after two 25 km drives! Never seen silicone actually combust yet. So keeping an eye on it until smoke stops.

According to ado it yourself website silicon will melt not burn

Badd rump roast!! Thanks for going in first! Lol!

I always fixed the rattles with a cutoff wheel.

 

Seems like it's not going to burst into flame, but it might smoulder until enough of it is gone.

Another 25 km run and I am sitting in beast trying to avoid the curing fumes after stopping. Stinks pretty bad. It ain't dripping out neither

I've never seen rtv melt once cured. Char from too high heat, yes. Dissolved by contact with fuel, yes.

are there any higher temp variants? i wouldn't think household stuff is paying attention to temperature in the same way as auto.

 

i've seen exhaust manifold gaskets smothered in RTV before i think...

Edited September 26, 20178 yr by idosubaru

Ultra copper will work as it's high temp, but as Dave said. lose the heat shield altogether.

Mmmm... Was general poroise silly stuff with a working range up to 150*C. Smell starting to disappear along with the curing smoke and the rettlehas not returned.Can't imagine how much ultra copper would cost by the cartridge!!

Copper is good for somewhere around double that.

I always tap around the heat shields to find the offending section, then grab the ears where they're bolted together with a pair of channel-locks, and bend them down, kind of half folding/dimpling the sides. Puts enough tension back in it to shut em up.

The curing smoke and smell is clearing up slowly. Pinching or bashing was thought of but I was in a lazy and creative mood. If they rattle again it might be a cut off wheel job. But this engine and exhaust is only temporary until I rehead my ea82t, fix my awd selector issue then this beast will be different again. Nearly thinking don't need turbo the way its going!!

For GL10 cross pipes that rattle, you remove the middle of three sections that occur on the engine right end of the cross pipe. Subaru does not make cross pipes anymore.  If the cross pipe has cracked at the turbo connection, about 3/4" down from the exit flange, you disassemble the heat shield around that connection, reweld the crack all around, and then reinstall the heat shield section.  Otherwise, that crack will leak and make a lot of noise if you don't fix it.

Well a week later and curing smell and smoke is all gone and just the tiniest of rattle if you can call it that, has returned. Happy with my approach

Cool idea mate.

Spoke to silicon manufacturer today on another topic and raised this one. Not that he knew how hot the exhaust can get he recommended what I used , roof plumbing stuff. He did offer that an acetic cure type silicone would have a higher working temp but may react with the metals

Yeah, If you are talking about the heat shields on the wye pipe......  I have had

those rattles........      Just loose the heat shield...Find out which one is loose and rattling....   cut it off  ... what ever you need to do to lose it......

Any of the silicons of know of will burn off exhaust. Leaving a gap that will accelerate corrosion. And yes the acidic ones won't help with that either.

Update...little bit off a buzz rattle sometimes but happy. I happened to be welding next to and right over fresh black silicone. Must say never seen silicon melt. Seen it char and burn to a crisp though