From the image that is the Exhaust Manifold.
The noise is likely comiing from a bad gasket between the bottom of the exhaust manifold and where the exhaust pipe connects to it.
With the engine running you should be able to feel the exhaust coming out at the connection. I usually hold a narrow sliver of paper near the connection and rev the engine to see if the exhaust blows the paper (which lets me know there is a leak ther).
If this is the case, it's usually not a hard fix, however the bolts which hold it on will often break (making it much more difficult). Spray them with penetrating oil before you begin work.
The gasket you'll need is # 31396 in the image.
Wednesday, July 24th, 2013 AT 11:50 AM