Vibration Questions

[2015g5.0]

So UPDATE / Hyundai Complaint / FYI / I have been waiting for a replacement wheel for over a month!!! Maybe this should go under dislikes?

I also would like so affirmation - the vibration is felt in my seat - I always thought / heard this is indicative of a rear-end issue i.e. tires or struts are bad in the back not the front - as the dealer is telling me (bent front wheel due to high speed pot hole impact and tire blowout). I can barely feel the vibration (at 80mph on the dot) in the steering wheel. I can feel it a bit in the accelerator but it is predominately in the seat.

I also notice that the vibration sometimes comes on around 65 gets bad to like 70 then dissipates then comes back at 80 and dissipates again around 90...it also kinda comes and goes on some roads its almost gone others it comes back like driving in washboard roads...any ideas? Does this sound more like tires? Sough

 

[2015g5.0]

UPDate - Wheel finally replaced and reduced/isolated the vibration to the rear. Turns out the rear/new Continentals were bad (out of round) and at 32,000 miles I had managed to warp the rotors. They put new tires on the rear and turned the front rotors but still had vibration. Purchased new rotors all around. I now have no vibration whatsoever.

 

[TbonePdx]

UPDate - Wheel finally replaced and reduced/isolated the vibration to the rear. Turns out the rear/new Continentals were bad (out of round) and at 32,000 miles I had managed to warp the rotors. They put new tires on the rear and turned the front rotors but still had vibration. Purchased new rotors all around. I now have no vibration whatsoever.

At 32K miles and assuming you don't race your car, the rotors were most likely warped by someone who didn't know how to properly torque the lug nuts when putting the wheels/tires back on your car.

Tony

 

[Florida Man]

I have a 2016 Genesis 3.8 sedan that has a sever vibration at idle. It started after the 15,000 mile service and the dealership has been unable to resolve the issue. It seems to get worse as the car gets hotter. The car idles at around 500 rpms. Seems a bit low. Anyone else having the same issue? Don't believe that this vehicle has an EGR valve.

 

[carguy75]

I have a 2016 Genesis 3.8 sedan that has a sever vibration at idle. It started after the 15,000 mile service and the dealership has been unable to resolve the issue. It seems to get worse as the car gets hotter. The car idles at around 500 rpms. Seems a bit low. Anyone else having the same issue? Don't believe that this vehicle has an EGR valve.

The rough idling could be from the gas your are using, especially if you are using regular. Hotter temps usually make pinging worst if the gas is the issue. If you use regular octane gas then you need to use the best quality gas available and avoid low-tier gas retailers. I recommend stations like Shell or BP.

Direct injection engines can use 87 octane, but due to high compression it would not run as smooth as if it was using premium octane gas. Especially if the gas is not a high quality gasoline with quality detergent to keep the fuel injectors clean.

I use mostly Shell 93 octane or BP 93 octane gas depending on where I fill up, and my engine purrs with a butter smooth idle. I would never use regular octane in my V8 engine unless under the most extreme emergency.

 

[Florida Man]

My engine is a V6. I tried running 3 or 4 tank fulls of higher octane but that did not stop the vibration from occurring.