I found this hole in my block that is making lots of noise due to air coming out of it like an exhaust.





Any advice on what to do with it? When I put my finger over it while it is running, it is a lot quieter.

 

That would be one of the holes for the air injection system. Since the cyl. head is installed so the hole is currently on the front of the engine, it should have a "freeze plug" in it. Looks like the plug is rusted out; fairly common. You'll have to remove the outer part of the plug & replace it. At least it's in the front....

 

Thank you very much.