4th bolt on manifold exhaust-pipe flange?

[alrock]

Didn't get a great pic but you can see it below. My new exhaust manifold had a fourth bolt on the flange that meets the exhaust - a second bolt at 12:00 above the three bolts that mount to the next exhaust pipe. Any idea on what it's for? One thought was maybe as an extra support for the manifold to help reduce stress cracks in the future, but it doesn't seem likely that they'd have a hard mount to the body due to NVH. Normally you have the rubber isolators to hang the exhaust.

What do you think the 4th bolt is for? You can see it below at the tip of the O2 sensor and it would be at the top position once the piece is installed.

 

[rascole]

I don't see a pic????

 

[rascole]

Ahh, now I do. Darn work website blocker.

Sent from my SPH-L710 using Tapatalk

 

[rsc]

Thats mighty strange. Might be a mix up at the welding station that day.

 

[4speedfunk]

Yeah...maybe its a Rocky Road manifold?

Oh-snap! :giggle: