Alright,


We have a 2003 Ion automatic with 95k miles. Yesterday, it developed a growl. Sounds just like an alternator going bad. But it ain't, lol. Starts being noticable around 32 MPH. Engine rpm does not matter, drive gear does not matter, only road speed matters. Applying the brakes doesn't change the sound, except for the decrease in speed. Popping it into neutral at speed doesn't change the sound. Nothing in the tires and no obvious defects to them.I thought probably wheel bearing, but even after 30 minutes at 75 MPH, they are only lukewarm and both sides are at the same temp. Has anyone run into this before?


Thanks

 

I have a 1997 Saturn SL and I'm not sure if the set up is the same. I would suspect the idler pulley or the tensioner pulley that the serpentine belt rides on. Tensioner pulleys are usually speed sensitve/meaning that they initially squeel at idle and when you depress the gas peddle and the noise lessens when you let off on the gas peddle. Idler pulleys growl all the time. Front wheel bearings are usually directionally sensitve. If you turn the steering wheel hard to the right while driving down the road you weight load the front left bearing and if you turn the steering wheel hard to the left you weight load the front right bearing.If your able to notice a difference in the noise when you perform these maneuvers, then I would still suspect a front wheel bearing. The transfer case would make the noise all the time irrespective of speed and direction. I actually jacked the front end of my care off the ground with two hydraulic floor jacks and used a stethescope to detect which bearing was making noise with the car idling and the transmission in first gear.There was no load on the bearings , but there was still a big difference in the noise level between the two. Good luck

 

Yeah this one has me stumped so far. Definitely not the idler pulley though, it has no relation to rpm, only to road speed. Doing the hard right and left maneuvers also makes no difference in the sound at all. I think it is possible it is a bad axle shaft, but I can detect no slop in them and the sound isn't like any bad axle shaft I've ever heard before, although I've never had a bad one in a plastic bodied car either. I'm going to jack the whole front end up and put it in drive after work today and see what I can tell.


Thanks