On my 98 jimmy automatic, when i come to a complete stop i get a humming noise. sounds like its coming from right in front of me, but when i put it in neutral, it goes away, then i put her in gear and the humm comes back [:-]. it just started doing this last night. as soon as i give her gas the humm goes away, untill i come to a complete stop. PLEASE HELP!

damn jimmy, one thing after another [:'(]

 

Check to see if the cruise or accelerator cable is leaning against the PCV valve hose. lastcoupe had recommended that for a gear clicking type noise that seemed to be coming from the dash, which isn't the same as your problem, but worth a look.

Its possible that you have a bit of a rough idle and it's just making something vibrate when in gear. You've mentioned that you've had your heatercore replaced. Dashes NEVER go back in the same way as they did factory new. Sometimes you get lucky and there aren't any rattles, more often than not...you do...

How loud is this humming? Is it a hum or a buzz? Have you checked your plugs for signs of fouling?

 

well Mr.lube did just replace the pcv valve so its quite possible. but if i rest my foot on the gas i can feel it in the pedal. I think she idles just fine, nice and smooth, plugs and wires were changed a couple months ago(ac delco platinums, $10 a piece!!) and i regularly use injector cleaner. the humm/buzz isnt too loud but i can clearly hear it over the engine. But feeling it in the gas pedal cant be good.......

 

Even more reason to suspect the accelerator cable on the PCV hose. I'd check that out first, making sure to zip tie the PCV hose cleanly away from the throttle cables.