Hello everyone.

I am a new owner of a 2009 (adventure package) H3. I recently had to replace the alternator and my local mechanics installed a new one from GM. Although it has no performance issues there is a slight whine present (just noticeable above the engine noise) when idling at around 600 rpm. It's not interfering with my radio unit, I can hear it under the hood too. When I accelerate it disappears. Mechanics claim everything was checked again and seems OK. Should I insist on installing a new alternator or might this fix itself after a while? GM's phone customer service was not of any help.

Thanks for your time!

 

DIY or get a Mechanic's Stethoscope to find the worn pulley!

 

@hummerz thanks for your reply.

I guess what I'm asking is if I should accept a brand new alternator with a very low whining sound or is that a sign of a lemon alternator. My mechanic doesn't seem concerned but my old alternator made no such sound.

Thanks again

 

Are you sure the noise is coming from the NEW alternator, or did they replace the alternator thinking that is where the noise was coming from? Regardless, noise comes from worn pulley bearings and won't last long!

 

Yes I was towed after I broke down, typical alternator death...radio went out, dashboard lights came on and battery completely dead, stalled again after jump start. My previous alternator performed quietly up until it's demise (11 years old) but the new one definitely is the source of the very low whine in idle (600rpm)

 

Btw, I checked my '07 OE alternator bearings and still normal! A few years back I replaced the idler due to whining noise at idle.

 

Did you receive the Service Charging System Message?

 

Sorry I'm new to the Hummer, Drove a magnum before. Once I was dead in the water and couldn't continue with a jump start I let the mechanics take over. They assured me it was the alternator. Kept the battery which is doing fine after the exchange.

I'm gonna see if they can have another look at Idler etc...Obviously the work and alternator are still under warranty. Thanks again for your input.

 

It's obvious the alternator NEVER failed! BTW:

 

Yup...they replaced them.


Thanks for all.