2009 Rami Hemi with 111,000 km (68,000 miles). Just noticed today a rattling sound from engine area when truck is idling. Does it when engine is cold or warm. Can't really hear it from inside the truck, but with driver's window down it is noticeable. I had a look under the hood and at first I thought it was coming from a fan pulley but that's not it. It's not an "internal" engine sound or a tick...it's more of a rattling sound noticeable at idle and low speed. Almost sounds like a loose heat shield.

I've seen a few posts about broken exhaust manifold bolts and I searched that, and maybe that's the problem but not sure. Just looking for ideas or suggestions of "common" issues that might cause this...before I get under truck and explore further. Appreciate any suggestions.

 

engine is reved to around 2500 RPM. Sounds like it's coming from upper area of engine bay. Can't pinpoint it though.

 

Mine had a ticking sound when the manifold bolts went bad. In the shop twice in 50,000 for them. Might have happened again to yours at 111K.

 

Thanks, Ramulak. Just to be clear, are you referring to exhaust manifold bolts or intake manifold?

 

Exhaust manifold bolts are a known problem with these hemis.

 

but manifold bolts are a "tick" sound not a rattle id pull off the belt and check all the pullys

 

This..or run it for a few minutes with the belt off see if the noise goes away. Even the serpentine belt itself can make some wierd noises sometimes.

 

truck with a friend today and we couldn't pinpoint where the noise is coming from. With the hood up, you'd swear it's coming from the top end or possibly the fan pulleys, but then we put the truck up on ramps and it sounded like it was coming from somewhere towards the rear underside of the engine. I took the accoustic manifold cover off and the noise didn't increase nor could I located it. Couldn't see anything loose. Best way I can describe the sound is a slow knock or loud metallic tick...if you rev the engine the noise frequency increases until about 1800 rpm then it stops.

 

I had something similar some years back with a company Caravan that did a noise very similar. It turned out to be the catalytic converter, a weld or something broke loose inside.

Something to consider.

 

Maybe timing chain, just out of curiosity?