Whenever I have the engine in park or am stop at a light, the engine makes almost a grinding noise with a virbration. It sounds like it's missing.

I've done a tune up and an oil change as well as added some dry gas. Still no fix.

It sounds fine when I'm on the gas or coasting.

Any ideas would be apreciated.

 

i was just talking to the wife and telling her about my truck doing the same thing it drives me crazy. do you have a 5.9? my noise is on the drivers side relatively close to me in the engine compartment obviously . but its thesame noise you describe. but my truck runs excellant and there is no hesitiation or anything i was almost wondering if something is vibrating against the firewall? i will be watching your post as this noise is irritating.