454 noise

[TC4x4]

The 454 engine that I have, is causing me to ask this question, I am hearing a knocking noise, it does not seem to be coming from the engine but the belts and pullies up front more, but it is hard to tell where for sure. It is pretty loud when i first start it up when it cold, but after it runs for 5-10 mins is quiets down and you can hardly hear it.

So what could be causing this annoying noise?

 

[4X4HIGH]

First pull all the belts off and this will tell you if it is caused from any of the accessories or if it's an internal engine issue.

 

[diesel4me]

I had a mechanical fuel pump bust the spring inside that bears against the rocker arm that does the "pumping" and it made a tapping/knocking noise ,that got quieter as the engine warmed up..I've had engines with timing chains so loose they slapped against the timing cover too,and once they warmed up it didn't make the noise as loud..one engine actually had a hole worn in the timing cover,it had been slapping against it so long....

Sometimes an exhaust manifold or header leak will sound just like a tappet or knock,and it'll slowly subside as the manifold or header warms up and expands ,and helps seal the leak some too..a stethascope is your friend when it comes to diagnosing engine noises..

 

[Greg Ducato]

I have had 454's produce engine slap noises when cold that all but disappeared when hot. I think this is a common big block trait on the Chevy.

 

[TC4x4]

That is what i have heard from a handful of people now, and yeah i goes away to where i cant hear it when its warm.