2012 Sedan 'Bucking'

[doity]

Hello all. This is my first visit to the forum. My girlfriend was in need of a newer vehicle and I suggested the Genesis as I saw one at a car show when it was first introduced and was impressed. She had never heard of the car before but she took my recommendation. I found a 2012 base sedan with auto trans with 45k at the local CarMax. We like the car so far but there is a issue with it that is making her kind of regret taking my advice.

The car has a habit of jerking/bucking under a few different circumstances. A couple of times when I have had it happen to me it was pretty severe. Once it happened when the rear trunk was full of heavy bricks and I don't think I was giving it enough gas (not freeway driving) and the car bucked pretty violently.

Once I got used to driving the car I kind of got into a rhythm about driving it. First off, the car seems to have a pretty heavy accelerator pedal and the car seems to like steady but light pressure on the pedal for good performance. She says that when the 'bucking' happens to her is during rush-hour bumper to bumper conditions and when driving slower.

We did our first oil change on it a couple weeks back and at under 50k the lube tech said that the rear differential fluid looked dirty and it did look a bit dirty to my eyes with some particles visible. I checked the manual and it says that during heavy use like stop and go driving it should be changed at 80k.

Has anyone else had this issue with the Genesis and would it be worth our while to either bring it back to CarMax or the dealership to see what the problem is? Would it be worth changing the rear differential fluid and/or the transmission fluid and see if that makes any difference?

I really appreciate any feedback as I want to keep her happy!

 

[dmitriylm]

I don't have experience with the V6's Aisin transmission but my V8's ZF unit is very smooth. Mine is nearing 70k.

 

[craigt]

Bucking is not normal in the 3.8 with 8 speed transmission.

As a comparison, my wife drives a Lexus RX350. When she drives the Genesis, she keeps saying it's smooth like butter. It's far smoother than the RX, with seamless gear changes.

The only bucking that MAY happen is when the traction control kicks in during hard acceleration. That doesn't seem to be the case with you.

Video tape the bucking (if you can't reproduce it on demand) and show it to CarMax.

 

[landtuna]

Why in hell would you have the trunk loaded with "heavy bricks"? This sedan is NOT a pickup truck and the suspension, although heavier than normal, is not suited for that kind of load. Do not exceed the maximum load rating for the car (should be on the driver door sticker and in the user manual).

My guess is that the tranny is searching for the right gear for the speed and load and is shifting back and forth. You need to take it to a good diagnostic shop to find out why - and I would not consider CarMax one of those. This could be the reason the previous owner ditched the car.

P.S. Differential (rear end) oil is normally very thick (90 weight or so) - almost the consistency and color of grease. If the differential has not been opened and is not leaking there should be no reason to service it before the specified time. You didn't say where you took the car for an oil change but I would find a reputable garage to do this type of work and not one of those 15-minute oil change places with teenage techs. You are asking for trouble there.

 

[doity]

Why in hell would you have the trunk loaded with "heavy bricks"? This sedan is NOT a pickup truck and the suspension, although heavier than normal, is not suited for that kind of load. Do not exceed the maximum load rating for the car (should be on the driver door sticker and in the user manual).

My guess is that the tranny is searching for the right gear for the speed and load and is shifting back and forth. You need to take it to a good diagnostic shop to find out why - and I would not consider CarMax one of those. This could be the reason the previous owner ditched the car.

P.S. Differential (rear end) oil is normally very thick (90 weight or so) - almost the consistency and color of grease. If the differential has not been opened and is not leaking there should be no reason to service it before the specified time. You didn't say where you took the car for an oil change but I would find a reputable garage to do this type of work and not one of those 15-minute oil change places with teenage techs. You are asking for trouble there.

well I have to say 'loaded down' in this case equals about 35 or less. I did not have the whole trunk stuffed full of bricks, no. I guess the thing to do is to take it to a good transmission shop and have them look at it. The car was originally a fleet car from NY and ended up for sale somehow in Oregon. Must had been for a exec. And you think any issues would had been ironed out by the fleet company previous.

 

[PMCErnie]

No doubt the fleet company may have ironed in this issue, not out.

CarMax will only help if you qualify. See below:

http://www.carmax.com/enus/faq/warranties.html#Can-I-return-my-used-car-if-something-happens-

 

[landtuna]

well I have to say 'loaded down' in this case equals about 35 or less. I did not have the whole trunk stuffed full of bricks, no. I guess the thing to do is to take it to a good transmission shop and have them look at it. The car was originally a fleet car from NY and ended up for sale somehow in Oregon. Must had been for a exec. And you think any issues would had been ironed out by the fleet company previous.

35 1 lb bricks doesn't seem like it would cause that kind of trouble as I am sure some Genny owners living in snow country probably carry several hundred pounds of sand during winter time.

The fleet use does sound suspicious though. I would take it to a good tranny shop and have them look it over.

 

[Mark_888]

I don't have experience with the V6's Aisin transmission but my V8's ZF unit is very smooth. Mine is nearing 70k.

Hyundai switched transmission in 2012 to the new 8-speed Hyundai transmission for both V6 and V8.

 

[Mark_888]

We did our first oil change on it a couple weeks back and at under 50k the lube tech said that the rear differential fluid looked dirty and it did look a bit dirty to my eyes with some particles visible. I checked the manual and it says that during heavy use like stop and go driving it should be changed at 80k.

If you want differential fluid changed, take it to a dealer. Don't let a place like Jiffy Lube do it. Also, either change the oil and filter yourself, or take it to a dealer. A place like Jiffy Lube (or similar) is not going to use the OEM filter, and this is not a common filter. If you were driving a common car like Camry or Accord it would be different, but lube places don't have much experience with a Genesis.

I would bet a lot money that the lube tech put the shavings in the fluid after it was removed from the car.

If your car is still under warranty, take it to the dealer and complain.

 

[craigt]

35 1 lb bricks doesn't seem like it would cause that kind of trouble as I am sure some Genny owners living in snow country probably carry several hundred pounds of sand during winter time.

Agreed. I haul 160 pounds of water softener salt (two 40lb bags over each wheel) on days it snows and I need to drive to work. Works a treat (with winter tires).

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[SixFootSix]

If still less than 50k, the car is covered by the 50k mile bumper to bumper warranty. I bought my Gennie 5.0 at CARMAX.

 

[FastDEW1]

Why hasn't anyone suggested taking the car to a Hyundai dealer? It's still under the factory warranty if it's a 2012 and around 50k miles.

 

[PMCErnie]

If still less than 50k, the car is covered by the 50k mile bumper to bumper warranty. I bought my Gennie 5.0 at CARMAX.

It's a 5/60,000 "limited" warranty, not a 50,000 bumper to bumper.

 

[doity]

Well, we took the car to the dealership. After a couple of test drives they were able to recreate the problem. They did a software update to the Adaptive Transmission and fixed the problem. Seems as if I was not the only one with the issue as I found other Genesis owners with the same problem and who had the software update.

When I called it 'bucking', I think others were calling the sensation a kickback which is probably more appropriate. For people who want to learn more about this in case it happens to them you can read the link below:


http://www.Genesis Coupe.com/drivet...ansmission-slip-issues-hyundai-corporate.html