Minor exhaust leak at exhaust manifold weld

JackC

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SECOND EDIT: Connected shop vac to exhaust pipe to pressurize exhaust system, and found several leaks at the weld.

The pointer stick in the one photo points to that stock weld area that leaks.
 

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billr

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Yes, if the manifold is off a magnetic-particle inspection ("magnaflux") can find any crack. It is a pretty common process, so readily available.

"Stock weld"??? That doesn't sound like an iron part to me, you avoid welding cast-iron as much as possible; it is not a normal manufacturing process. Looking at the pictures, I think it is a steel (or SS) fabrication; would be much easier to repair.

Did you see smoke coming from that exact spot the stick is coming from? No chance the smoke was coming from behind nearby heat-shields?

Post the test results, let's see just what bad emissions values you need to reduce.
 

eddieguy

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Connected leaf blower to exhaust pipe to pressurize exhaust system, and found NO leaks when spraying soapy water around manifold.

I definitely saw smoke coming out at the shop. It was a cold engine so I see no way they could make fake smoke. I saw this test with my own eyes. I feel it was a legitimate test. But neither I nor they could tell exactly where it was.

Now even if the manifold is removed I do not know if anyone can find where the mystery leak is in order to weld it.

Other than visual inspection is there any way to find the leak after the manifold is removed?

The stick in the one photo points to the stock weld area that the smoke appeared to be coming from.
yeah I don't think they would try so hard to con you as to try to produce fake smoke but at the same time I don't see how a smoke test could be mandatory. They do seem like they really push the Authority on what they consider an acceptable repair.

I tried a similar repair didn't have much success with the J-B Weld but I'm sure my leak was probably significantly bigger. I've had good success with J-B weld on different things I broke my transmission mounts on a 88 Nissan Pulsar jb Weld held it together for almost 2 years but dealing with high heat that's a whole other story
 

billr

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You may be able to find the crack, with manifold in car, like this:

Coat the area with some refrigerant dye, maybe diluted with oil (probably any kind of oil). Let it sit for a while, maybe even soak a paper-towel and slap it on the area. Wipe/rinse off the surface and get out your UV light. If the whole area still glows, keep wiping/rinsing. The crack should retain some dye long after the "open" areas are wiped clean. This is the essence of the "dye penetrant" (Zyglow) method used for non-magnetic metals. Got a plastic manifold? That would take a "spark test", subject for another day...

Oops, I just saw your second edit, you found the crack1
 

JackC

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"Stock weld"??? That doesn't sound like an iron part to me, you avoid welding cast-iron as much as possible; it is not a normal manufacturing process. Looking at the pictures, I think it is a steel (or SS) fabrication; would be much easier to repair.
I think you are right Bill. I am so old I only know cast iron headers. These are smooth, not bumpy like old cast iron manifolds.

So, now is there a better chance I can do some type of cold repair?
 

grcauto

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I think you are right Bill. I am so old I only know cast iron headers. These are smooth, not bumpy like old cast iron manifolds.

So, now is there a better chance I can do some type of cold repair?
Have it brazed or welded.
 

billr

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You have a much better chance of getting it welded in-place, since it isn't cast iron. Sorry, nothing has changed about the chances for JB working.
 

billr

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A friend of mine has a shop with a welder probably good enough to fix that in the car, but the shop is in Auburn. I expect it would be a free job.
 

JackC

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Can you get a mig welder tip to the crack?
Unfortunately not.

After investigating all the putty, wrap, epoxy, etc products available on the market today, non are good enough for a good permanent repair on a manifold IMHO.
I was hoping something new had been devloped since I was in the field years ago. But non of the reviews proved that to me. Most products did well on tailpipes and mufflers but not on super hot manifolds.

A local shop will R&R the manifold and have it welded Monday April 5. My age prevents me from doing it myself.

Thanks to all of you for helping with this decision.
 

dabunk

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Unfortunately not.

After investigating all the putty, wrap, epoxy, etc products available on the market today, non are good enough for a good permanent repair on a manifold IMHO.
I was hoping something new had been devloped since I was in the field years ago. But non of the reviews proved that to me. Most products did well on tailpipes and mufflers but not on super hot manifolds.

A local shop will R&R the manifold and have it welded Monday April 5. My age prevents me from doing it myself.

Thanks to all of you for helping with this decision.
It kills me now as well to have to hire someone to do work for me!
 

billr

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In my case, for the '97 van, it will be because of our PRC (People's Republic of California) regulations. I am feeling my age, but that is not the most objectionable limitation in my life.
 

JackC

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Fixed and smoged. I had the manifold removed and took it to a muffler shop and had it welded at a broken factory weld. I took it back to the shop that removed it and he was closed for the day. Thanks goodnes he was closed, because I took the manifold home and filled it with water and it leaked at the new weld. Took it back to the muffler shop had it rewelded and I water tested it again. Success. Took it back to the shop to have it installed. Took it to the smog shop and it passed.
 
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