I'm having a humming issue only around 700-750 rpms. It hums the entire car and it's rather annoying. The car will sometimes idle below that and not make a sound, or sometimes idle right at that and hum until I start accelerating again. I think I've narrowed it down with my mechanics stethoscope and it seems to be humming at the part circled in red. Does anyone know what this part is called? Anyone had any humming issues before? The cars runs like a top otherwise.
EDIT: Seems to be coming from the rear of the motor, still around 700-750rpms. Could this possibly be a mount?
Edit to the Edit (1-15-14): Got it up on a lift today to check for any under car sounds. Sounded like it was all coming from the transmission, but I did not want to accept that. I took the serpentine belt off and ran it for 30 seconds to see if the sound went away, and what would you know, it did! So putting the stethoscope back on, I found it to be the alternator. So I'm going to have the alternator and power steering pump replaced within the next week or so. It has a slight leak, which we all know will kill the alternator. I guess it was bound to happen.
EDIT: Seems to be coming from the rear of the motor, still around 700-750rpms. Could this possibly be a mount?
Edit to the Edit (1-15-14): Got it up on a lift today to check for any under car sounds. Sounded like it was all coming from the transmission, but I did not want to accept that. I took the serpentine belt off and ran it for 30 seconds to see if the sound went away, and what would you know, it did! So putting the stethoscope back on, I found it to be the alternator. So I'm going to have the alternator and power steering pump replaced within the next week or so. It has a slight leak, which we all know will kill the alternator. I guess it was bound to happen.
Lead Lap
That's the cover to one of your two ignition coils. Never heard one hum but might be time to change it out.
I think I'm gonna pick one up and see if it changes anything. Anyone else have info on what the humming might be? It's coming right from that circled area. When I put the stethoscope on it, it hums like crazy.
Replaced the coil tonight with a brand new one, no change. But I think the humming is vibrating through the engine and releasing at the coil. I sort of traced it back to the rear of the engine. Does anyone think this could be a transmission mount issue? The car doesn't shake at idle, smooth on the highway, I just don't know. Any ideas?
Lead Lap
Could just be vibration from bearings in the timing chain assembly or the injectors pulsing. I would take the serpentine belt off and spin all the accesories by hand and check for bad bearings.