No chance its a manifold - head gasket problem.

Dont think so mate, if there was i wudda ripped the cunt off long ago :lol:

i'll check tho

is there not a heat shield between the cat & the floor pan also?

gesus this is an old post!
i took that heat shield off months ago, and its still rasping, its deffo the cat methinks

i have a ecotec cat f/s

as mossy said the heat shield on manifold downpipes rattles

follow yor exhaust down under the car where the two pipes join into one there is a heat shield there as well these always come loose i have cut mine off, check this.

Car starts and idles quitely and runs perfectly without any unusual noises upto 4500rpm when it starts to rasp and about 300-400rpm after it stops.
think fadscorsa may be right,could be the cat.i could replace all possible parts which could by doing it by elimination,but that wud cost too much :mad:

check ur CAT mine did that when i had a 1.4 16v the CAT was resonating :(

start the engine and listen if its loose

I would have thought even if the exhaust gasket was cracked or rusted or broken,it would be on so tight that it wouldnt be able to vibrate.
it anoys the poo out of me,but not enough to take the whole exhaust manifold off to see if that is actually the problem!

take a look underneath :)

Ah right,i'll have to inspect it more closely ,dont fancy movin all those pipes and bits to get in there :(

cheers kris

my bros does this, basically the manifold gasket has gone and it vibrating against the block.

Im tryin to track down a nasty metallic rasp which is rev specific (4500rpm) and rekon its comin from the exhaust manifold area.I ve removed the manifold heat sheild and that wasnt the problem. so was wonderin what these parts are
- I think its the egr valve- it seems to originate from the bottom of the manifold and has alot of silver piping,goes into a little metal pot right at the front of the engine bay and then comes out of the pot with a black pipe and ends up in a black sort of cylindrical plastic box, just in front of the battery.
im just goin through all the possible options and checking all possible loose bits that could resonate at 4500rpm

any comments appreciated