transmission delay shifting

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hangout

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Location
New York
Car
Infiniti Q70L
it's so cold this winter, while I pull out the FX35 in the cold morning ( under 10 degree ),,
the transmission reacted so slow.
shift in D, need to wait for more than 5 seconds to feel the tranny engaged. if i press the gas within the waiting period, the car just feel like in the N gear, idle up, but going no where.
after the car warm up, this situation will disappear, back to normal.. ( delay for 2 second )
my friend told me that he had the same issue on his G35, tranny delay shifting for 2-3 second in normal condition, normal temperature

is the transmission going bad? or just the manufacture defect ?

my 2007 FX35 is AWD with 68k miles
 
I noticed this I think last week when it was cold, where it lagged shifting from reverse to drive. I'd worry less about it if it only happens when cold and you don't notice the issue otherwise. I'm not sure what actually does the shifting, but if it's hydraulic then it could just be the fluid is so viscous from the cold that it's slower to shift. Do you ever have issues shifting between gears like 1-2-3 etc. or just between R-N-D?
 
Check your fluid level. Fluid expands when it heats up. So if fluid is slightly low and it's very cold, there will be shift lag until it warms up to operating temp and expands. I had the exact same symptoms a while back when I was low on fluid.

The shift process is basically

- TCM sends signal to specific solenoids to shift (there are ones for reverse and the gears).
- Solenoids open/close to move fluid to specific passages in the VB.
- The fluid is what actuates the shifting.

So if fluid pressure is low, there will be a lag. Also, if fluid is more viscous from cold, it's pretty much the same as low pressure so again, lag. Once car warms up, fluid is expanded and flows easier so no more lag.
 
Is there any downside to maybe adding a little extra fluid to combat when it's cold and the fluid might be lower?
 
I notice this in the frigid cold weather as well. There will be a delay and then I might also notice a delayed shift from 1-2 as the car warms up. Once everything is warm, all is well.
 
happen between R-N-D in the real cold weather, for more than 5 seconds.
under the normal temperature, the tranny react slow between R and D also, like around 2-3 seconds.
but it shift just fine 2-3-4-5 or down shift.

---------- Post added at 03:49 PM ---------- Previous post was at 03:46 PM ----------
shadow191 said:
Check your fluid level. Fluid expands when it heats up. So if fluid is slightly low and it's very cold, there will be shift lag until it warms up to operating temp and expands. I had the exact same symptoms a while back when I was low on fluid.

The shift process is basically

- TCM sends signal to specific solenoids to shift (there are ones for reverse and the gears).
- Solenoids open/close to move fluid to specific passages in the VB.
- The fluid is what actuates the shifting.

So if fluid pressure is low, there will be a lag. Also, if fluid is more viscous from cold, it's pretty much the same as low pressure so again, lag. Once car warms up, fluid is expanded and flows easier so no more lag.
Click to expand...


I didn't check the fluid level,, since it happened in cold morning while I start to go work.
and always forget to do it while it's normal.

the best way to check it?? cold morning keep the engine running, not doing any shifting at all before it???
 
Not 100%, but I don't think the fluid will warm up at all unless you drive it. If it sits in park, it's not circulating fluid since nothing is rotating. It's also not pumped to the radiator which helps to warm fluid up. Better to drive it easy for a while and let it shift, that's what warms up the fluid. I always check fluid levels after a drive.

---------- Post added at 01:19 PM ---------- Previous post was at 01:17 PM ----------

There's a fluid fill range just like oil. I tend to keep mine close to the high limit. From my understanding if you overfill your transmission, you risk froth/foam and air in the fluid. That can reduce the effectiveness of the fluid and also impact shifting. I haven't had any experience with overfilling so I don't know if that's common or not.

StuLax18 said:
Is there any downside to maybe adding a little extra fluid to combat when it's cold and the fluid might be lower?
Click to expand...
 
I want to say checking the transmission fluid level is not as easy as checking the oil for example. I think I remember the FSM saying to use the consult to see what the temperature is because it needs to be within a certain range to give a good reading. With that said, the dipstick may have a warm and cold side, so you might be able to check it when cold and get a good reading.
 
Probably the case; on my 335i, you have to get the transmission to operating temperature when filling fluid or you'll be off. So you have to shift the car on jackstands to circulate fluid. That car doesn't have a dipstick though, so it's harder. For the FX, I just check after normal driving, I'm going on the assumption that it should be somewhere close to operating temp.

On the FX, there's only one reading which is for warm. I can't remember ever seeing a cold line. And of course the car has to be on.
 
I had two FXs
from my experience, the tranny on the FX really react slower than others ( between R-D or D-R ),, just much worst in the cold weather.
my friend told me that, actully it's the Nissan programming issue,, even the 2009 FX has the same issue.
nissan worked that out after 2010+ FX..

so, even normal days, I drive very carefully everytime I park or pull out FX.
Past few weeks, the FX feel like don't want to shift at all,, scared me out.
not sure if it's related to the fluid level yet, will go check about that
 
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'07 and '09 have entirely different transmissions and programming. 09+ is when they went to the 7 speed and that's the one where there was a TSB for the programming to fix lag. For the 5 speed on the 1st gen, I'm not aware of any reprogramming to fix lag. The FX transmission and programming are pretty much identical to the G/Z for a given model year. I swapped a 350Z valve body into my FX along with TCM for a while and it was a direct bolt on and plug in, no mods. Shifts were the exact same.

I don't find the FX transmission to be that bad relative to others. If it's all functioning properly, it's fine.
 
shadow191 said:
'07 and '09 have entirely different transmissions and programming. 09+ is when they went to the 7 speed and that's the one where there was a TSB for the programming to fix lag. For the 5 speed on the 1st gen, I'm not aware of any reprogramming to fix lag. The FX transmission and programming are pretty much identical to the G/Z for a given model year. I swapped a 350Z valve body into my FX along with TCM for a while and it was a direct bolt on and plug in, no mods. Shifts were the exact same.

I don't find the FX transmission to be that bad relative to others. If it's all functioning properly, it's fine.
Click to expand...

I don't mean it's really that bad, actully it's really similar to the BMW auto tranny (I had three of them, all automatic ), need to wait for around 2 seconds to engage gear.
I used had a Infiniti I-35, I like that tranny more than FX, not sure they are the same part.
 
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