spamsushi

I have an exhaust leak from the exhaust manifold and headers because of a couple snapped bolts. Is there an easier way to fix the leak without drilling out the old bolts? maybe a sort of sealant?

TomCat39

Sealant can only do so much. Without the bolts to hold the pieces together securely, no amount of sealant will be able to compensate for a lack of fasteners (nuts and bolts).

VeeSykkz

the leak is caused by a broken bolt, not a bad gasket. get an "ease out" to remove broken bolts.

holmesnmanny

No sealant will ever work on exhaust parts. Period. Then the sealant will burn onto the oxygen sensor causing even worse drivability issues.

spamsushi

I just changed the gasket and it all worked out. No more leaks

F22Master

This is not true, I have successfully used sealant many times on exhaust systems. BUT, the mating surfaces must be in good condition, and all hardware must be present and properly used.

EGCTR

JB weld works well, and resists some-what high temperatures.

TomCat39

I totally agree with you. My favorite gasket maker for exhaust joints is Loctite 30558.

Granted, I wouldn't use any gasket maker up on the head to EM joint. But I do use it on every joint after that on the exhaust system. For the head to header, I just plugged the exhaust holes on the header and sprayed the red permetex ultrastick onto the mating surface then placed the gasket and then placed the header and bolted her up to spec.

holmesnmanny

Are you guys being serious? There is no way in hell gasket maker or sealant of any kind will work to seal an exhaust manifold which is what the op is asking. Maybe down by the muffler post-cat . Just look at that rating on that loctite sealant.. its only good to 600 degrees. The exhaust manifold easily goes beyond that.

TomCat39

If you read my previous post (as in first post of the thread), I already mentioned no sealant would work for OP's issue. Also of note I said I didn't use a gasket maker at the head joint (the hottest spot of the header, the first bend). My two piece header, I used Permatex copper (700 degree intermittent) and the loctitie for backside of cat joint on back.

After a year of driving and the outer edges of even the header joint don't surpass 700 degrees as the gasket maker is still not "burnt away". I had to use it to rehabilitate the metal/graphite gasket by putting a small coating on each side of both metal pieces and putting it back together. It sealed up the imperfections of the joint and has kepted it sealed where it was just starting to develop a very slight exhaust leak channel. Only the interior part of the joint see the extreme high temp. The rest of the flange and piping helps distribute the heat thus reducing it to level the gasket maker can withstand. I figure by now the inner part of the joint is filled with carbon adding another layer of protection to the gasket and gasket maker in the joint.

The one thing I didn't like about the copper was that it has to sit for 24 hours before putting to use while the loctite only needs 3 hours.

Also of note, the O2 sensor was before the first joint with any gasket maker material for a few weeks before relocating to just before the cat. So any material on the inside edge that got "burned off" never got near the O2 sensor. The joint was pretty established before the o2 sensor went downwind of the joint.

But no, I didn't say sealant can make up for broken fasteners, I was saying sealant can make up for for faulty gaskets for exhaust joints and sharing my favorite sealant for exhaust joint jobs. For holes in piping you need exhaust sealing wrap that bonds via the heat. Doubt it would work on the header though only post cat I believe.

mike_1212

Op, easy-out the broken bolts.... replace gasket and install new bolts... trying to sidestep the issue and not doin it correctly will result in having to do it again.... and again.... do it right the first time and save yourself a headache later...

F22Master

I use sealant on turbo setups between the manifold and turbo. Thats about as hot as you can get in an exhaust system, and I havent had any leaks yet. Ive done it multiple times on different cars, never a leak. I just use the "muffler patch" sealer stuff. Its like $4 for a big tube of it. Works great!

http://m.autozone.com/autozone-mobile/en/accessories/VersaChem-5-oz-muffler-and-exhaust-repair-kit/_/N-25hw?id=710676

holmesnmanny

Sry but im politely calling bs. If you are only using sealant and not a metal crush gasket anywhere around the exhaust manifold its going to leak. Period.

Furthermore, there is no point using sealant when you're using a crush washer anyhow. If you are using both and its not leaking then its because of the crush washer. That sealant will burn off in 50 miles or so.

F22Master

What kind of proof do you want?

holmesnmanny

Even tho i didnt use a question mark, there are a couple questions in my post to you. You could answer/elaborate/clarify what it is.

mike_1212

Hmmm. Didnt post... try again... i agree with holmes. Those " sealants" cant withstand the temps we are talkin about here... especially under boost! There is a reason that these joints are designed without them! Proper hardware, crushwashers, proper torque! Why are installation instructions so hard to follow? Its hot plumbing.... not rocket science.

F22Master

I have used sealant both with and without gaskets. It holds up just fine and like I said, I have never had a leak when sealant was used.

I HAVE had MANY leaks even with brand new crush gaskets, and surfaces that were ground completely flat. Took them back apart, put some sealant on both sides of the gasket, toque it back down, and no leaks since (several months, several thousand miles).

KevinEF7

Permatex copper is definitely my go to when assembling a personal exhaust

But just to put it out there, you CAN fix a head-> header flange connection with furnace cement. Ive seen it done MANY times on derby cars, they sell it in small quart tubs to patch your house fireplace and such, rated to 1600 degrees or so depending on brand, only costs about 10 bucks a jug. Downside is 24 hour cure time. It really does work.

It is a bandaid obviously if you are trying to fix a head connection, but obviously for a derby guy thats perfect as the cars are near disposable