, the weird humming may be a wheel hub assembly. For me it sounds kind of like a groaning, can (barely) be felt in the pedal and sound like it's emanating from low in the firewall. I've noticed that it's usually most prominent at 45-50 MPH. You can usually get an idea of which hub it is when going around a curve. The outside wheels take more weight due to the vehicle rolling opposite the direction of your turn. This additional weight makes the failing hub groan more noticeably. Conversely, turning so the failing hub is on the inside will usually make the noise completely stop as weight is removed from that side... depending on the severity of the roll. Sorry if you already knew this. Hopefully it's useful to someone.
Basically, louder turning left = right hub, louder turning right = left hub.
Out of warranty cost for GM part... about $500, but as much as I drive that lifetime warranty is worth the cost.
I guess I should also update my other info.
182k miles on a 2009 LTZ 3.6L bought new in August of '09.
I've had the following non-consumable repairs done in that time:
-Two Front Passenger Wheel Hub Assembly (1 IW, 1 OOW)
-One Front Driver Wheel Hub Assembly (OOW)
-One bent wheel. More a problem with crap roads than manufacturing.
The Bluetooth/On-Star module isn't working at the moment, but I've not had time to check it. It may be something simple... dunno.
Other than that things are OK. It has the occasional squeak, I think I need to change the front strut mounts, and that crappy plastic wing-nut holding the spare tire down has broken.
A few of things to note:
- Headlights suck to change in this car. If you've not had to do so, be prepared. There are a couple of videos online about it, but I can make another if for some reason they're not available. It's not a simple done-in-ten-minutes job, but it's not impossible.
- Michelin HydroEdge are great on this car, but they're out of production. I'm breaking in a set of Michelin Defenders currently and so far I'm pleased with the performance. No snow or ice to speak of in the area yet. You'll probably have to order them since few stock the odd size (225/50/18 on the LTZ), but they're nice.
- Draw-Tite receiver hitches fit perfectly. You can't see the main cross-member of the assembly. Only the end of the receiver shows.
Three things this vehicle has taught me to check on my next purchase...
- Is it a common tire size? (Um, not on the LTZ)
- Are the headlights reasonable to install? (LOL)
- Does the passenger side wiper inhibit the driver's view? (On the '09 Malibu the passenger wiper stops in the middle of the driver's viewing area.)