'06 Hummer H3 separated cat/exhaust manifold

[D60]

Ran into this today, looks like the cat has blown away from the EM. I find a couple reports of this -- seems like EM cracks are more common on the I5

Looking at aftermarket, they sure look MIG welded, although from what I can see it looks like OEM was something like induction welding?

I wonder if this can be welded back together with pre and post heat? I'd be concerned about proper clocking, too

The guy doesn't have a lot of money, so it's either bottom dollar aftermarket or fix this one. No emissions testing

@GMBoy

 

[GMBoy]

Ran into this today, looks like the cat has blown away from the EM. I find a couple reports of this -- seems like EM cracks are more common on the I5
View attachment 194154
Looking at aftermarket, they sure look MIG welded, although from what I can see it looks like OEM was something like induction welding?View attachment 194155

I wonder if this can be welded back together with pre and post heat? I'd be concerned about proper clocking, too

The guy doesn't have a lot of money, so it's either bottom dollar aftermarket or fix this one. No emissions testing

@GMBoy

Asolutely a common problem. I replaced one and half butt welded another. Both solved the problem at the time. Replacement is the best option but budgets do vary and if you weld it correctly it will last awhile.

 

[D60]

Asolutely a common problem. I replaced one and half butt welded another. Both solved the problem at the time. Replacement is the best option but budgets do vary and if you weld it correctly it will last awhile.

Tentative plan is to order a Walker from RA.

Did you have problems with clocking/fitment on the one you welded? I only ask because apparently these manifolds are made of glass and I'd be concerned a less-than-perfect fit might unduly stress the manifold.

 

[Mcbeem5]

Check out this forum , do the search engine it is covered alot.The older colorados had I-5 motors.

Chevrolet Colorado & GMC Canyon Forum

A forum community dedicated to Chevy Colorado and GMC Canyon owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, towing capacity, maintenance, and more!

www.355nation.net

 

[GMBoy]

Tentative plan is to order a Walker from RA.

Did you have problems with clocking/fitment on the one you welded? I only ask because apparently these manifolds are made of glass and I'd be concerned a less-than-perfect fit might unduly stress the manifold.

To be honest with you, mine was not in the same location as yours, it had cracks between the runners so an easier job.

 

[atikovi]

The guy doesn't have a lot of money, so it's either bottom dollar aftermarket or fix this one.

Then why is he driving a Hummer?

 

[Thermo1223]

Then why is he driving a Hummer?

I wouldn't call an H3 a Hummer. More like a Colorado with more/covered storage.

 

[D60]

Also I think some people are thinking this is a cracked manifold or a cracked-anything.

No, it's 100% clean separation where the cat is apparently induction welded (I guess?) to the manifold. It's just virtually impossible to get a pic up there with my phone, but I observe a uniform ring of darkness at the joint like an induction weld -- there is no obvious filler and no tearing (which would be expected if filler material were used)

You can grab the exhaust pipe and move it all around by hand.

Somehow they're bonding mild steel to a cast iron manifold, and the failure was clean through at that joint. I have found at least one other mention of this on the I5, but the majority of threads and vids I've found are about cracked manifolds.

 

[Mcbeem5]

The manifold and cat are 1 unit right, Wouldnt it be considered a broken or cracked manifold weld? The colorado forum has recommendations for new manifolds , a number of companies make them.P,S, alot of I 5 owners have broken off several manifold bolts changing out those manifolds.

 

[dumkid]

No emissions? Just buy a cheap header then, and put a sensor spacer as needed

 

[Astro14]

No emissions? Just buy a cheap header then, and put a sensor spacer as needed

For the current owner, that may be the case, but emissions are tested in parts of Colorado.