Need a Super High Temp RTV or similar product

Ok, I still have a cracked manifold and really don't want to take everything appart to replace it just so it can crack again. I tried using the Thermo-Steel stuff, and it worked for a while, but it eventually cracked appart. I even used some fine mesh to strengthen it, it held for a while, but it eventually cracked appart.

After using some high temp red RTV to seal a leak in the Magnaflow catback on my Eclipse (for some reason all but one of the pipe junctions use flanges, the other uses a clamp), I got to thinking. If I could find an RTV sealant that could withstand the 1200+ degree temps of the exhaust in the manifold, I could patch the crack with something flexible that wouldn't crack.

Is there any thing out there that will withstand the high temps of an exhaust manifold and still be flexible. Most stuff I find will dry hard, I think this is why the patches eventually fail.

Permatex has a muffler and tailpipe sealer, but I can't find out if it cures hard or not.

Does anyone know of any other products out there that might work.

hmmm, mighty putty?:dunno:, haha

I think Gumby can take the heat. LOL!

Why do you keep breaking the manifold? Put in a good NEW replacement, add a stainless steel flex tube in the downpipe where it crosses from left to right of the vehicle, and replace your engine and trans mounts.

I think the reason that it keeps breaking the "patches" that I try to make, is because the tube is cracked all the way around the tube. New engine and trans mounts are on my list of upgrades to do next. I plan on doing the mounts, manifold, and SYE all at the same time.

I just need something to get me by until I get everything replaced, because the tractor sound is annoying.

Also, good replacments are hard to find for the Renix XJ's. All of the ones I see that seem to hold up good are for the HO engines

Replace the manifold and move on with life, it'll be quicker and probably cheaper than fiddling with patches and so on.

I don't see the need for adding a flex joint but am probably in the minority there.

JJacobs said:

Replace the manifold and move on with life, it'll be quicker and probably cheaper than fiddling with patches and so on.

I don't see the need for adding a flex joint but am probably in the minority there.

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I would replace it, but I am not going to replace it until I get new mounts, and I am got going to get new mounts until I get an SYE.

You can use the 91+ manifolds.

You will need to add two bungs--one for the EGR tube, and one for the o2 sensor. If you lack the welding skills any muffler shop can do it for you.

The two bungs are the only difference.

Did it crack because of the stress on the exhaust system from a tcase drop?

joe_peters said:

You can use the 91+ manifolds.

You will need to add two bungs--one for the EGR tube, and one for the o2 sensor. If you lack the welding skills any muffler shop can do it for you.

The two bungs are the only difference.

Click to expand...

don't want to get off thread, but Thanks for that! I didn't know that was an option

winkosmosis said:

Did it crack because of the stress on the exhaust system from a tcase drop?

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It was cracked before the drop.

joe_peters said:

You can use the 91+ manifolds.

You will need to add two bungs--one for the EGR tube, and one for the o2 sensor. If you lack the welding skills any muffler shop can do it for you.

The two bungs are the only difference.

Click to expand...

or if you're not in an E-Check area you can just EGR delete it. Just make a plate that seals off the EGR bung on the intake manifold, removed the EGR stuff on te drivers fender and plug all the vacuum lines.

How about going to midnes muffler or muffler shop and have it welded????? maybe

The 4.0 header cracks there because of how long the tubes are + thermal expansion/contraction, IMO. It's a design flaw. I've only seen a few that weren't cracked. I don't feel like replacing mine repeatedly so I'm currently considering welding a flex joint into one of the pipes right before it goes into the collector, I think that should reduce the stress enough that the darn thing will stop cracking.

You might also consider putting a 49-state/federal emissions (no precats, but more O2 sensor bungs) downpipe/exhaust system in, blocking the extra O2 sensor bungs and installing one if there isn't one after the two pipes combine. I believe this would be legal since it is adding more modern components to an older emissions system.

I tried welding it, but since it is cracked all the way around, it can't be fully welded. I don't want to go through the hassle of removing it just to put it back in without replacing it with a new one.

If I can't find a good sealant, I may just go ahead and remove it, take it to school, sand blast it, tig it, and beef it up. I have a month before school starts and I am looking for projects to work on, so this might be a good one to do.

Sounds like a good plan to me. I would beef it up a bit AND make it more flexible in certain spots so that you don't just move the failure point.