Sebasmartinez Posted October 11, 2023 Hello group!need some help. 2012 NV 2500 4.0 from 0mph to about 35mph… no hum , don’t feel anything on steering wheel or any vibrations in the car… as soon as I approach 40MPH this hum appears…the faster I go, the louder it gets. FIRST DIAGNOSIS: wheel bearing changed them and sound changed slightly, different, at first I thought it was quieter, but no, it was different SECOND DIAGNOSIS: tires are bad, internally the have bumps on the pattern… so struts are bad and wheels are bad…so I changed both front tires… NOT the struts So…. Get on high way and as soon as I pass that 40MPH… sound is back….. can’t figure what it is …. can the struts cause the loud sound? what else can it be? would really appreciate your help Quote Share this post Link to post Share on other sites
OpenRoad Posted October 12, 2023 Can you provide more info? So it is a sound only and no vibrations? Does the sound change when under load (going up a hill) or no load (coast down a hill)? While coasting down a hill in nuetral? Does the sound change with light braking? Any difference when cornering? Difference between left and right cornering? Did this sound just start suddenly or has it been quieter in the past and is now getting louder? Is the sound only tied to speed or is it engine rpm? How many miles on your vehicle? Just trying to come up with more clues that might point you in a direction for further investigation. Quote Share this post Link to post Share on other sites
Sebasmartinez Posted October 12, 2023 Hi OpenRoad! Yes, would really appreciate any clues you can provide! answers below: Can you provide more info? Yes So it is a sound only and no vibrations? No noticeable vibrations out of the regular road feel…. So would say vibrations are to a minimum at all speeds sound yes, starts at 40, humming goes up as speed is up. its more of a (sound… wwwwaaaaaaaaaaaaa ) then (sound ….. wwaaaawwwaaawwwaaawwaaa ) at 80mph it continues to sound, different pitch or frequency but doesn’t lower volume the hum at 60 is more annoying or done-ier Does the sound change when under load (going up a hill) or no load (coast down a hill)? While coasting down a hill in nuetral? sound changes a bit when going left or right….. when I steer right it lowers volume a bit light load Our hills here are bridges, but going down on neutral the sound still is there. Does the sound change with light braking? No and I have no vibrations on steering wheel while breaking Any difference when cornering? Difference between left and right cornering? yes… to the right lowers volume a bit and to the left makes it just a bit louder, but not loud loud Did this sound just start suddenly or has it been quieter in the past and is now getting louder? it started suddenly. Can has been great, no sounds before Is the sound only tied to speed or is it engine rpm? Speed rpm is smooth How many miles on your vehicle? Just hit 110K thanks for reading OpenRoad! Quote Share this post Link to post Share on other sites
OpenRoad Posted October 14, 2023 Sorry for the slow reply, had things come up. So any suggestions I might make are strictly from a wag perspective (not a trained professional mechanic) so take them for what they are worth (not much). Since there is sound but no vibration, and the sound frequency increases with speed (not engine rpm) then some rotating equipment (drive line, axles, wheels, ..) but not necessarily due to imbalance. Since it doesn't seem tied to engine load (going uphill versus coasting down) and the sound changes when cornering I would suspect something in the front wheel hubs or rear differential/axles. If you can safely elevate the rear of your van on stable jack stands you might try running the engine up to the 40mph equivalent to see if you can hear anything and perhaps pinpoint the location more. Low frequency noise is inherently hard to place where it is coming from, especially with other road noise when you are inside the vehicle. Sorry, this isn't much help. There is always the run it till the problem gets worse and you can more easily identify it. Good luck. 1 radin2son reacted to this Quote Share this post Link to post Share on other sites
Local Apparent Friday Posted October 15, 2023 @Sebasmartinez Did you get it aligned after replacing all the stuff? Scalloping on the tires is generally an alignment issue. Also, what tire are you running? Some are just loud. 1 radin2son reacted to this Quote Share this post Link to post Share on other sites
