Strange noises from motor under load

[Pure Evil]

G`day guys,
I`ve got a strange rattling noise from the motor when I accelerate and when I kick down going up a hill. It is even worse when towing my boat. Mechanic says it could be a hairline crack in the exhaust manifold.Sounds like a tukka tukka more than a pop. Could it be the heads, timing chain, etc..etc. Best to ask the best brains around on this forum

Thanks
Pure Evil

[alby1976]

Quite possibly a crack in one of the exhaust manifolds, common thing to happen to the standard exhaust manifolds on the V6's.