rlim13

I bought a 07 Lexus GS 450h and wanted to know if anyone has experienced a severe hestitation in accelaration? I was getting onto the freeway and jump on the gas. My car moved quick like usual but this time at about 50-60mph it started to hesistate or stall Couple seconds it started moving again. Being new to hybrid technology I'm not sure what to expect. I want to say it felt like a bog or miss fire but it didn't feel like your usual bad spark plug sputter. I mentioned it to the dealer during my last service and they said sometimes when you smash on the gas pedal the computer sometimes stalls because it needs time to process all the information. Is this common or should I be more concerned and push the dealer to look at my car again.

Thanks for any info it be greatly appreciated.

bigblack06

iTrader: (20)

Well flooring it won't help but,I'm intrested what others say as I also just purchased a 450h.

Coolpop

I posted about this last year when I bought my 07. I wouldn't say that the acceleration issue I continue to experience is severe, but there is a noticeable hesitation (maybe 1-2 seconds) when I floor it. It's always been like that. I've asked some guys at the dealership and they say it's normal, but I'd like to get a more unbiased opinion.

lucasb7

I think there are two issues presented in this thread. Throttle response, or the time between hitting the accelerator and power being transmitted to the ground, and the shift in the 2-stage planetary gearbox.

My car has very little throttle response lag--really nothing I would complain about. If yours has some and it bothers you, I would reset the transmission's learning. I don't recall how off the top of my head but you can find it online or the dealer can do it for you.

The pause at ~55 mph is the shift between the two planetary gearsets. This is one of the differences between our cars and the Prius. In order to have gearing that provides good acceleration at low speeds and higher top speed, they had to have a two stage gearbox. This way, the car has more options on where the engine is revving at a certain speed. The change between gearsets is around 50 mph.

I've posted about this before but you can visually and aurally notice the change at around 14 seconds in this video:

http://www.youtube.com/watch?v=cbv1i6GvE7s

rlim13

Thanks Lucasb I'm looking into reseting transmissions learning. Thanks again for your time

LexPushaD

Did this work because my 2008 has a hesitation in exceleration. it did it the other day. Should i get the gas filter changed, and get the fuel enjectors cleaned?

rickyb80

1-2 seconds is a pretty long time. I understand the gearset change but if you're experiencing a severely noticeable delay I'd take it in for a look.

bigblack06

iTrader: (20)

Well I was told by the tech when I brought it in that the hestation was based on a saftey mechanism when you floor it.

rlim13

I took my car to have them check on what it may be. They said there are actually 2 gears in the GS 450. Sound basically what Lucasb7 talked about..."2 stage planetary gearbox". But I think in my case I think the "shift" is longer than others. Especially compared to the Youtube video. I think its a problem that most don't have or others don't even experience depending on how they drive. I basically pay more attention when I accelerate. I ease off gas to let the car "shift" smoother at 55-60mph. I really don't think it's a safety feature. Think if you were entering freeway and you attempt to merge that hesitation at 55-60mph and you are unaware of the "shift" pause. Anyways I plan to take it to another mechanic and get a second opinion. I try posting any info I get.

man0fsteel

I've had my GS450h since Nov 07 and I've noticed the half second delay when I punch it. Nobody that has driven my car including myself notices any delay at 55 mph when flooring it though.

LexFather

I've actually started to notice this sometimes too. Never happened before but happening recently. Gonna tell my dealer..sparkplugs maybe?