2008, chevy, trailblazer 4.2

When i start the engine I get a noice like a hole in the exhaust system. The RPM jumps to 1K and eventually returns to normal. As the engine warms up the noice level lowers alot. I did pull the manifold heat sheild back as far as I can and started the engine and could not feel any blow-by. The noice seems to be comming from around the manifold area. Any help would be greatly apprecipated.


1 thought on “2008, chevy, trailblazer 4.2”

  1. If it sounds like a hole in the exhaust, it may be a leak around the exhaust manifold. A manifold gasket may have burned and is now leaking. These are difficult to find but you may try to look for signs of carbon or black carbon build up around the area of the manifold that it is leaking from to confirm a leak.

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