Engine/transmission stutter on deceleration

[petekarn]

Am curious if anyone has experienced this. Have less than 3K miles on my 4.6 Genesis. Whenever I let the engine decelerate, at about 25 mph the engine/transmission makes a brief stuttering sound, then the sound stops. I am not braking at all during this, but it almost sounds like the sound the anti-lock brakes make when they kick in, only very, very soft. If the the radio is on even at a medium volume, it is not audible. However, you can feel it ever so slightly.

If it continues I'll take it in for a look. Thanks.

 

[TJPark01]

Am curious if anyone has experienced this. Have less than 3K miles on my 4.6 Genesis. Whenever I let the engine decelerate, at about 25 mph the engine/transmission makes a brief stuttering sound, then the sound stops. I am not braking at all during this, but it almost sounds like the sound the anti-lock brakes make when they kick in, only very, very soft. If the the radio is on even at a medium volume, it is not audible. However, you can feel it ever so slightly.

If it continues I'll take it in for a look. Thanks.

What you are hearing may be the transmission downshifting at lower speeds. Compared to other automatics that try to get to top gear and stay there to maximize gas mileage, the ZF tranny in your car is very good at downshifting and being in the right gear all the time. It's not perfect, I mean what car is, but the transmission in this car is one of the best auto's I've ever driven.

 

[ctrcbob]

I do feel the transmission when it downshifts, but I don't hear anything.

 

[TJPark01]

I do feel the transmission when it downshifts, but I don't hear anything.

yes, you feel it more than you hear it. But if you turn off the radio and roll down the windows you would hear it. Just from what the previous gentleman described is what I'm going on.

 

[bskinner]

Yes, I too experience that stutter/shutter when it downshifts at 20-25 mph. Curiously, it is intermittent and I have yet to discern a pattern, now at 8K. Not having the slightest idea re: transmission stuff, I figure if it was something bad news, it would be a constant thing. Have had a lot of cars, but this one is my "soulmate." Then again, I live in S.C. - home of the LovGov and perhaps easily infatuated? Comment - on the tranny - I mean.

 

[ImInPA]

The sound you are hearing/feeling is most likely the lockup torque converter unlocking. If you allow the vehicle to simply slow down on its own, this is more noticeable. I have experienced it in many cars. Lockup torque converters are more fuel efficient because, once locked, they eliminate the slip inherent in automatic transmissions. The lower gears are more noticable than the higher gears.

 

[Seattle Genesis]

I get this 'lock up' when I slow down to cross over speed bumps. Once over the bump I barely hit the pedal and the car lunges forward. very annoying. So what I will do is just come to a stop then accelerate. I guess its just learning to drive the Genesis.

 

[petekarn]

Thanks for the replies and info. Since I'm not the only one, it's probably in the design. Still learning....

 

[bskinner]

Yes, indeed. Thank you very much. Heading in for my 8K oil change this afternoon.

 

[faylo]

iv had a customer come in for the exact same complaint..
i know they have a fix for this on the V6 transmission but not on the V8.

just hang in there im sure they will have a flash for the transmission soon.

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[Bastet]

Yep, I too felt the car completely shutter very noticeably a few times under those same conditions. I even felt it through the steering wheel and seat. Once the car warmed up, the problem went away.

It doesn't happen all the time and, like you, have been unable to reproduce it on demand yet. But the explanation makes a lot of sense though.

I'll continue to monitor the situation and should anything further develop, I'll kept you guys informed.

 

[BorregoV8]

Thanks for the replies and info. Since I'm not the only one, it's probably in the design. Still learning....

Take it in, have the Dealer Service person drive it see what they say.

 

[ctrcbob]

Take it in, have the Dealer Service person drive it see what they say.

"I'm sorry Mister So-and-So, but we have not been able to duplicate the problem".

 

[BorregoV8]

"I'm sorry Mister So-and-So, but we have not been able to duplicate the problem".

Yea, I have heard that same story several times myself. If all else fails try a different dealer.

 

[petekarn]

Had my car in for regular service today and mentioned the stuttering. The tech said he hadn't heard that complaint before. When I mentioned that it might be a software update (as suggested in this thread), he said he'd check. And sure enough, there was an update. Haven't been able to discern if it fixed it or not because it is more noticeable when the car is cold. Will check tomorrow morning.