idle and a knocking sound

shaun M said:

When 5.9L is idling it has loose like knocking sound. Could this be the harmonic balancer and if so can this be fixed without hours of frustration.
Truck runs good besides that.
Plenum fix. Hughes kit
Iac sensor and map changed

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It can be the balancer however they don't usually go bad. But it is possible so don't let that cross you. It could also be the flex plate it could be loose, it could be valve train noise a loose rocker arm. Their are so many things that can emulate a knocking noise. The funniest ones are when the hoods vibrates lol

shaun M said:

Found out my knocking sound was the water pump pulley.
The bearings were shot and grinding.

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Ahh, I find it hard to believe that bearing makes a knocking noise, bearings make a smack sounds or more commonly a bearing noise lol. But bearings make rumbling sounds, whirling sounds, whine sounds, smacking sounds, all kinds of sounds. Sound the sounds sound sounds.