Manifold

[AMCLOVER258]

I am preparing to get a geo prizm back alive for DD while i do the head swap. upon just checking everything out i realized theres a circular whole in my manifold- probably a stupid question- but whats it for? it almost looks like a canister of some sort once went there.. i will be switching to a header once the swap is complete so its not really affecting me much however my curiosity is killing me.

[IowaEagle]

Where is it located on the manifold and what year engine and which manifold?  Intake or exhaust.

[AMCLOVER258]

Right below where the intake and exhaust are bolted to the head. 83 258 its got like aluminum hosing that was once around it but may have been pulled or fallen off. Im at work so i unfortunetly dont have any pics

[1985amceagle]

would it be the hole circled in red?

[AMCLOVER258]

Hahaha on the money just alot more dirty!

[1985amceagle]

a tinfoil like tube originally ran from that port to a port in the air cleaner, and until the engine was warm enough for the vacuum system to activate, and move the flap at the snout of the air cleaner, the air was pulled from near the exhaust manifold.

[AMCLOVER258]

Ahh so if thats missing will that make my engine compartment loud? cause it sounds like half my exhaust comes from the tail pipe and the other half from under the hood? Hopefully soon ill have a header on there with the 4.0 head but its kinda embarrising how loud it is now..

[1985amceagle]

No, it is only a way to gather heat from the exhaust manifold, it is not pulling air out of the exhaust, just what is around it. I think it has more to do with improving how the engine runs in the cold, than anything else.

[Mernsy]

Make sure your manifold bolts are tight. They can back off on their own.

[AMCLOVER258]

Ok cool. Yeah i dont have any more than a week until i get this other DD running and then ill start stripping off everything. HOPEFULLY the inside of the engine looks good!