Help!!!!

[ranger28]

when my truck gets to high hpms then when it changes gears you get a raddling noise?? you dnt hear it at adle nore when driveing normal what can this be?

 

[Big Jim M]

Once more

when my truck gets to high hpms then when it changes gears you get a raddling noise?? you dnt hear it at adle nore when driveing normal what can this be?

When the engine is running at rpm above 2200 and isn't pulling..just getting the job done.. The vac is at it's highest and the throttle opening is at it's lowest so the computer advances the timing and leans out the fuel mixture to the best mpg and power.
If there is a little morcompression due to some carbon built up in the chamber the ratio becomes higher than the factory has allowed. So you get that rattle.
Some call it valve clatter.. A few say it is clicking.. But it is all the same. The quickest way to manage it is to use the next highest octane fuel available. This fuel may take the rattle out of your ride.
Sometimes the rattle is caused by a little vac leak in the intake system.
Big JIm