[honks]

my 95 sierra is making a fairly loud tapping noise that appears to be coming from the exhaust manifol would this be a sign of the manifold being cracked i cannot see the manifold as the heat shield is still attatched and all the bolts are rusted up

[skitzlux]

if its like a tapping or a ticking sort of noise it will more than likely be your manifold gasket blown out

[Gwagensteve]

Or the wire mesh gasket that sits between the manifold and the downpipe. They can crack or get mashed up causing a leak. Pretty common.

I don't think sierra manifolds are prone to cracking to the point they audibly leak.

I know G16A Vitara manfolids are known to fall apart.

Steve.

[royce]

get some redex engine treatment, follow the instructions about dribbling it down the carby, all leaks will stand out like dogs balls after that