Noise only when accelerating

[stevieP]

Sounds like a blowing exhaust manifold gasklet ( mechanic thinks so too ). Took a/c comp off etc to get at bolts, no sign of leaks. Have adjusted tappets, not that but engine feels tighter again. Only happens when accelerating hard or when I rev quickly. Doesn't happen if I accelerate or rev slowly. Anyone got ideas ? Could it be low quaity oil, oil filter, fuel filter, supermarket fuel, injectors, ?

[stevieP]

90 % sure it's exhaust manifold gasket. I'll strip it 2moz.

[geeves]

could also be inlet manifold under boos of a leak further down the exhaust

[walruz]

Agree. Had similar problem. Stripped complete exhaust side off only to realize it was actually
inlet gasket doh. Upside was now have new gaskets, resurfaced manifold, replaced
broken studs (why is it always the one closest to the firewall) new turbo, hoses ect ect.....