The manifold weighs 17lbs, stainless. The manifold is about 5 years old, I am the third owner. The crack continues up and down the other side, the same as pictured. All the other welds on the manifold look good with no cracks anywhere else. I painted the manifold with flameproof VHT paint.

Should I have it repaired? There is no exhaust going through the crack.

 

Just have someone re-weld the crack. No big deal.

 

Yeah it needs to be re welded or the crack will get bigger.

 

Have them back purg it too.

 

^ what is this? I dropped the manifold off today.

 

Back purging is when a welding gas ( usually argon, helium, or a mix of the two) is used inside the part being welded which displaces oxygen and ensures no sugaring ( little metal booger looking things) occurs inside the manifold runner/collector as they like to break off and eat turbine wheels.. it also ensures complete or near complete weld penetration assuming proper steps are taken for pipe fitment, amperage, filler rod selection, and how the piece is welded (root pass with a cover pass or single pass, pulsed, etc. )

The reason it probably cracked in the first place was probably from a poor weld with minimal penetration, sloppy fitment of the weld joints and simply usage. I.e. heat cycles, , high egts, vibrations from things like stiffer/solid motor mounts, , no flex pipe on the downpipe, weight of the turbo, etc

If your guy cleans it properly and uses the correct filler and amperage and has decent welding skills it should be a simple repair

If you say it goes around that whole collector weld here's what needs to really happen. Your welder needs to grind the weld out into a deep vee shape so when he rewelds the joint you get proper penetration instead of just making a cover pass which does nothing to address the crack structurally, it simply takes the cosmetics of the crack away

 

No exhaust is coming from the crack so i don't think it needs to be back purged...?

I will call the shop in the morning and ask if he can grind down the weld a bit before re welding it

 

It still needs to be back purged. I always back purg with argon. It's SS it will sugar, when fixing a crack you want it to fully penetrate to the inside. Like said before if the welder will just go over the crack that will mask the problem not fix it.

 

ideally the ends of the crack should be drilled before welding but it probably isn't feasible in that location.