4.6 Transmission Downshift

[AZGeny]

After combing this site for a couple of months finally picked up a ‘10 4.6Tech the first of May . I love the car so far but there are a couple of annoying things I wanted to get feedback on from other members.

First, when coasting to a stop there are noticeable down shift points at around 42mph (most annoying) and somewhere in the 20s (not so annoying as usually breaking at this point). I have owned/driven dozens of cars with auto trannys and never noticed this in other vehicles.

Second, under light acceleration from a stop the car surges (accelerator pedal is very sensitive/non-linear) then at about 5mph the transmission shifts up causing a noticeable drop in acceleration. Remember seeing this mentioned in another thread but believe it was on an ’09 so assumed was rare or had been corrected in the ’10 versions since there wasn’t much additional discussion.

Test drove the car 3 times prior to purchase and did not notice these traits so not sure they are developing or just distracted with all of the other cool features. Are these characteristics normal for the Tau/ZF drive train or something I should ask my dealer to address?

Thanks for any input.

 

[ASHDUMP]

I don't think your car has a problem because my Genesis does the same thing. There has been a couple people on this site that have bought a sprint booster and recommend it. I think there was some mention that it corrected the downshifting as well. I use the word "corrected" loosely because I think the car was designed they way it is operating.

I can not vouch for this because I do not have the sprint booster. I might purchase this item though.... just not sure when.

 

[TruRed1]

I've noticed the same annoying downshifts after taking the foot off the gas in my '09 4.6 Tech. I'm in my first few weeks of ownership, and this is just one of the annoying aspects of the Hyundai drive that has me considering dumping the vehicle. I was previously in a '03 Lincoln LS V6 and loved the smooth transmission in stop and go, city driving...but not so much with the Genesis.

I have the same problem with light acceleration...which has to occur since the Genesis downshiifts you into nothingness when the gas pedal is not applied. I attributed the surge to the V8 (this my first), but wasn't sure. Whiplash will surely abound if I don't get out of this vehicle.

After looking at the sprint booster video, I'm not sure this will help my issue, and for $330, not sure if it's justified. http://www.sprintboostersales.com/detail.cfm?year=2009&make=Hyundai&model=Genesis&engine=Gas

Back to the service department to wear out my warranty is my first step. Ownership 29 days. In the shop 6 already, geez.

 

[Seattle Genesis]

Same here with the surging. almost took out my garage door. One more reason my Genesis is now in storage..

 

[Dimitry]

First, 41/42 is right around where the car gets into 6th. Any below, and it's too low to maintain sixth gear, and will shift into 5th, creating that movement. I would suggest to either cruise control at 44 or higher or in 5th under 40. You can also manually shift to 5th gear and get it in cruise control.

For your second issue, I would suggest starting by letting the car roll when you let go of the brake (if you have a non-10' auto-hold) or start in second gear (shift over and shift up)

One thing I miss from one of the cars I used to have was a second start feature, where it would always start from second gear, nice and smoothly.

 

[ctrcbob]

One thing I miss from one of the cars I used to have was a second start feature, where it would always start from second gear, nice and smoothly.

One of the reasons I did not buy a Lincoln LS, back when they first came out was because they would always start from 2nd gear. To get a 1st gear start, you had to go to manual mode. I hated that 2nd gear start. I understand that in later years, the Lincoln LS 5 speed was changed to start in 1st.

 

[jkohn]

The downshifts don't bother me, they have the advantage of keeping the engine RPM's a little bit higher so that when you go to accelerate there isn't that lag due to being in the wrong gear. My G35 was even more aggressive in this regard, so I don't see it as a problem in the Genesis.

As for the "lurch", my 4.6 only does this when the engine is still cold, and it's never been as severe as other seem to be reporting.