I’m living in Saudi Arabia and in a relatively small city so I got very few professional mechanics here.
I’ve Hyundai Sonata 2011 bought preowned a year before, from that day (didn’t know this issue before buying) I’m having this issue that car is making very loud humming noise on high RPM like 35000+ whether it’s still or on road, so rule out the possibility of worn bearings or other tires related issues because it’s of high RPM even on parked car and there is vibration that also increases accordingly as noise. I showed it to my usual mechanic he said immediately change the transmission fluid I said I’ve already changed then he said show it to some transmission mechanic, so I went to transmission guy he said there is no problem in transmission this sound is coming from Exhaust Manifold or something related to it, I went to the guy who deals with exhaust system he said there is no problem in Exhaust System. I keep on visiting different mechanics for this issue some said this is normal some said we don’t know keep driving like this, nothing serious, one guy told me to change Engine and Transmission Mounts as this maybe because of excessive vibration, so I changed whole 4 mounts, but still noise exists. This thing is really becoming headache for me as no one’s there to diagnose this.
Then I found a thread on this website (will give link if someone asks) stating same issue for Hyundai Sonata but for older model that is 2004, he said that the problem was in Harmonic Balancer or Crankshaft Damper or Crank Pulley Damper, he wrote the other two names in bracket and upon searching I think they are all the same (if they are different please explain), I asked to my usual mechanic he said this sound couldn’t be because of pulley, but I found on thread that the guy who explained his problem; is very similar to mine but the question is his car is 7 years old model than mine, should I go for changing Harmonic Damper?
I’m sorry for going too long as I’ve to tell the whole year story.