I've noticed recently at Idle while the engine has warmed up that I've developed a consistent vibration. The vibration lasts for about a second or then goes away and comes back. It doesn't feel like a rough idle and engine RPM's stay the same. I've cleaned MAF and TB with no luck.

My question is where to start looking? Vacuum?

You can feel it anywhere on the truck EXCEPT the motor?

 

A/C compressor?

 

Oh... E fans?

 

AC is off.


I know my alternator is starting to take a **** I dont know if that has anything to do with it?

 

I suggested a fan might be unbalanced because you said it comes when the engine is warm, and my fans run a second or two at a time like that.