I know these thinks can be tricky on a forum, but my 166 has started to make a noise under full load.
When accelerating there is a zingy rattle coming from I thing the back of the engine, if I accelerate slowly it does not do it, will not do it at all revving the engine when stationary. Typically it occurs at 2-3k rpm, its not road speed dependent, no issues like rough running, all of which makes it a bit trick to diagnose. It does seem to be getting worse
There is a bit of exhaust noise from the below the rear bank, not felt anything yet as that undertray is in the way, (front bank seems in order) are there any heat shields under there as I am thinking one is vibrating? I do not think it is pinking, does it with it without STR or hot / cold that may vary the mixture. Next stage I am thinking is take off the aux belt and see if it gos away, then off with the undertray.
Any other pointers/experiences to share?