Engine making strange rattle noise?!?!

[James1000]

Ok before Anything else:
-end of last year the car had 80000k engine installed
-January had a pulley, the belt, aircon compressor replaced
-Was serviced 3 weeks ago
-Hit a piece of metal on road while driving last week and put a small hole on bottom of manifold (which I temporarily fixed with muffler putty)


Now today I noticed it making this inconsistent rattling noise which seems to be coming from left hand side of engine.

Any ideas as to what it could be? before I take it to mechanic.

[Surge]

Does it have stock heat shielding on the exhaust manifold?

Not sure if the h6 has that but maybe that's what's rattling or something stuck inside it?

[James1000]

Not sure ill have a look tomorrow, hopefully its something simple like that.

[Stevo3RB]

Does the rattling occur at certain revs, 2500-3000RPM? If so, could possibly be the chain tensioner. If you do a search you'll find a fair bit of info on it...