Fo350z

First, I want to say I apologize if this topic has been previously addressed. The Search feature... isn't so great. (Even when you set it to search topic only, it doesn't, and seems you can't do a search for more than one keyword - if you do, it does an OR search, not an AND - I tried using plusses, quotes, AND, etc, no go).

I have an 06 Touring AUTO Z, that I purchased brand new on Sept 23, about 3 weeks ago. Anyway, I've started getting this.. kind of bucking when it switches gears. It feels a lot like it is low on fluid. In other words, I will push the gas and nothing will happen for a moment then it will 'lurch' a bit into gear, or if I am holding a steady throttle and the car wants to upshift, it seems to come out of one gear, hesitate, then lurch into the next. It's very apparant and extremely annoying when I'm stuck in beltway traffic (a huge part of the reason why I bought the auto over the manual to begin with).

I have found other threads about bucking transmissions, however they all seemed to deal with manual and not auto (or were ambiguous to the point that I could not tell if it applied to my situation).

As I mentioned, it feels quite like it is a little low on tranny fluid (my previous car, a 97 grand prix gtp, had a trans leak and after it lost enough I had this same feeling). I went out just now to check the fluid level. Maybe I'm just blind, but after searching over the engine bay I did not see a dipstick for the tranny fluid. I then checked my Z's manual and of course under 'auto tranny fluid' it says 'take it to a dealer to get it checked'. Now, thats precisely what I have in mind for my next action, however before I did this I wanted to make a post and see if this was possibly normal with the Auto Z's transmission. It's not a horrible bucking, but very apparant and after about 5-10 minutes of stop and go traffic I am very very frustrated with it.

So, any input on this would be much appreciated! Thanks in advance.

Ilov350ZEE

iTrader: (11)

have it checked

PythonLaX

iTrader: (1)

Not sure whats wrong but mine doesn't do that. Does it do the same thing in manual mode? I'd definitely take it to the dealer, thats what warranties are for.

Fo350z

Thanks for the replies guys.

I found out something interesting on my way home from work this evening... the car continued doing the bucking for the first part of the ride home. I then shifted to manumatic mode and stayed in that mode for a few lights, then switched back.

Once I switched back the bucking had stopped and shifts were smooth again! I haven't used manumatic mode very much, and honestly don't even know if I had used it since I first started noticing this bucking issue - my guess is thats when it started but I hadn't put 2 and 2 together.

Hopefully it will stay smooth now. I only have 900 miles on the car, and haven't even gone above 4000 rpms yet for the breakin period!

HighwaySpeed

+1

Suvlaki

Do you mean something like when you tap the gas a bit, it takes a small but noticeable moment before you really feel an increase in acceleration? My A/T '06 Z seems to hesitate in D, especially if iv'e been crusing for a while and I tap the gas a bit to get a small accel. It feels as if the engine needs to get in a good big breath of air before it starts to go to work. On the other hand, when in my Manumatic mode, there is no hesitation. I feel a torque increase to the wheels when I tap the gas instantaniously.

I think that the D mode has been designed to be more of a cruising, driver-friendly mode by smoother longer shifts and smoother acceleration. When in Manumatic mode, it knows you're ready to party, and shifts faster and harder, and provides instant torque.

At least to me, the car feels completely different torque-wise and accel-wise between D and Manual modes.

Aggro_Al

Is it cold right now where you are at? If so, it may take a while for the tranny to warm up. Also, don't help the tranny shift by lifting your foot off the throttle while shifting. Trust me, you are not helping it. Try to keep up level or accelerating throttle when upshifting. If you are driving aggressively, a buck or kick is normal the 5AT can shift faster than an eyeblink when driven aggressively. You may also experience a clunk which is normal when the car shifts from 2nd to 1st in auto mode. This is normal. Do not try to add or change the transmission fluid yourself. The tranny is sealed and is fill-for-life under normal conditions. The parts and the fluid are Nissan proprietory so have a qualified Nissan tech inspect and repair it.

Aggro_Al

If you're cruising, you are most likely in 5th gear. The tranny does not know you want to accelerate until you step on the throttle and apply enough of it to register you want to accelerate quickly. In auto mode it will then kick down to 4th or 3rd. If you switch to manual mode while you are cruising, you will automatically drop the tranmission from 5th to 4th while changing modes. The tranny does it automatically because downshifting would be the only reason you would be changing modes when you are already in the 5th gear, which is the highest gear. You wouldn't need to manually shift to 5th if you are already there.

Suvlaki

Ya, I know that, but my tranny does not shift when I tap the gas because I don't tap it enough. One of the cool things about this transmission is that it teaches itself to understand what the driver wants to do. It knows when I want to shift gears in D, and I can tell when it shifts from 5th to 4th. However, what I mean by tap is a very light tap... enough to register an acceleration command, but not enough to register a "please downshift because I want to accelerate a bit faster" command.

The feeling is kinda hard to explain but if you were in the car with me, I'd be able to show you. It is a very subtle hesitation that, however, is not present when in manual mode. It would make sense, seeing as the shifts are quicker and firmer in manual mode, that the computer treats D in a more relaxed, cruising, driver friendly way. This may account for the small hesitation... to give you a smoother acceleration.

Anyways, I have hijacked this thread so please nobody comment too much on what I have written... my post was originally a question to the OP.

Fo350z

It's not so much when I was cruising, but rather when I was completely stopped it would 'thud' into first gear when I pressed the gas, or if I was in say 2nd and it wanted to shift to 3rd, it would thud into that gear.

I for the most part drive it in D, I think I've only used manumatic twice so far. Good info about the tranny, I didn't know that about it being closed like that. Also, I do keep on the throttle when it shifts (I don't leave up for the shifts, in D or manumatic).

Thanks for everyone input!

DanielW

iTrader: (27)

when i switch to MT mode and shift into third its really rough and kind of jerks into third anyone experiencing this?

Aggro_Al

It's normal if you are driving above 40mph or driving aggressively. You're going from an unlocked gear to a partial lock gear and the jump from 2nd to 3rd is a pretty good jump. Also, if you are driving aggressively, the tranny shifts faster with the slight jolt.

Suvlaki

Yeah, read my thread.

https://my350z.com/forum/showthread.php?t=.....