7AT question/possible issue help

GZ3 · 06-17-2015, 12:04 PM

Recently on some spirited runs Ive noticed my cars transmission doing something odd. Basically just crusing going about 65-70, go WOT,usually the car just drops gear and takes off. But this time it seemed to almost double rev(?) while it hit 3rd and took off. Like you would hear/see the engine and revs shoot up and then grab the gear and go. I hope that makes sense...but you can hear the engine go "ruumm' *once...then "ruumm" twice and on the second rev is when it took off... anyone heard of this before? has happened a few times already thanks

SouthArk370Z · 06-17-2015, 12:35 PM

Sounds like low fluid level to me. Possibly a weak pump. Edit: That's going by my experience with much older auto trannys. Could be a lot of other things with a TCM-controlled transmission.

With the proper OBD/CAN software, you can monitor/log transmission parameters to get a better idea of what's going on.

kenchan · 06-17-2015, 02:09 PM

please elaborate more on the "ruumm" sound.

vtec to vvel · 06-17-2015, 02:18 PM

most likely downshifted twice to a lower gear (ie downshift once to a lower gear (first rumm), and then downshifted once again to another lower gear (second rumm). its possible depending on the speed/gear your car was in at time of WOT.

FPenvy · 06-17-2015, 02:21 PM

was this in manual or auto mode?

if you downshift at the moment the tranny is auto downshifting you'll get a double downshift.

GZ3 · 06-17-2015, 03:19 PM

Quote:

Originally Posted by FPenvy

was this in manual or auto mode?

if you downshift at the moment the tranny is auto downshifting you'll get a double downshift.

It was in normal D, just floor it and it does one rev to match rev then it kinda revs again and this catches gear and takes off

From 60 mph it can only drop to 3rd gear though is what worries me

GZ3 · 06-17-2015, 03:20 PM

Quote:

Originally Posted by kenchan

please elaborate more on the "ruumm" sound.

It was ruuuummmm!! Then RUUUUUUUUUUUMMMM! Lol

FPenvy · 06-17-2015, 03:31 PM

Quote:

Originally Posted by GZ3

It was in normal D, just floor it and it does one rev to match rev then it kinda revs again and this catches gear and takes off

From 60 mph it can only drop to 3rd gear though is what worries me

what do you mean it can only drop to 3rd at 60mph and that worries you?

sounds about where you'd want to be for a drop the WOT run at those speeds even 4th as well.

critical · 06-17-2015, 03:36 PM

how do you know what gear you're in? you're in D.

it's probably just downshifting, then realizing it needs to go to a lower gear. doesn't really sound like a problem

vtec to vvel · 06-17-2015, 03:47 PM

Quote:

Originally Posted by GZ3

It was ruuuummmm!! Then RUUUUUUUUUUUMMMM! Lol

thats vtec yo!

please post audio of you doing this

GZ3 · 06-17-2015, 03:50 PM

Quote:

Originally Posted by FPenvy

what do you mean it can only drop to 3rd at 60mph and that worries you?

sounds about where you'd want to be for a drop the WOT run at those speeds even 4th as well.

Thats what i mean, between 60mph and about 75mph the transmission shouldnt be shuffling around for gears. 3rd is the only option at WOT. It feels like the car blips the throttle then grabs gear and goes... Instead of dropping gears and going all at once like normal. Im gonna do the fluid flush here ina few mins

GZ3 · 06-17-2015, 03:52 PM

Quote:

Originally Posted by critical

how do you know what gear you're in? you're in D.

it's probably just downshifting, then realizing it needs to go to a lower gear. doesn't really sound like a problem

If you ever want to know what gear your car puts you i. At wot whild in D, just tap it over to manual mode and youll see it in the tach

GZ3 · 06-17-2015, 03:52 PM

Quote:

Originally Posted by vtec to vvel

thats vtec yo!

please post audio of you doing this

Vtec??!!! Lmao... I want my VVEL back hahah

6spd · 06-17-2015, 03:55 PM

Some one say rum?

FPenvy · 06-17-2015, 03:56 PM

Quote:

Originally Posted by GZ3

Thats what i mean, between 60mph and about 75mph the transmission shouldnt be shuffling around for gears. 3rd is the only option at WOT. It feels like the car blips the throttle then grabs gear and goes... Instead of dropping gears and going all at once like normal. Im gonna do the fluid flush here ina few mins

how many miles are on the car?

how often do you drive in manual mode?

06-17-2015, 12:04 PM	#1 (permalink)
GZ3 A True Z Fanatic Join Date: Dec 2009 Location: SATX Posts: 3,296 Drives: Z Rep Power: 22	* UPDATE7AT question/possible issue help Recently on some spirited runs Ive noticed my cars transmission doing something odd. Basically just crusing going about 65-70, go WOT,usually the car just drops gear and takes off. But this time it seemed to almost double rev(?) while it hit 3rd and took off. Like you would hear/see the engine and revs shoot up and then grab the gear and go. I hope that makes sense...but you can hear the engine go "ruumm' once...then "ruumm" twice and on the second rev is when it took off... anyone heard of this before? has happened a few times already thanks __________________ 09 GT-R 12' 370Z 7AT HANDED DOWN 12'+13' 5.0 SOLD Last edited by GZ3; 07-17-2015 at 02:52 PM.

06-17-2015, 12:35 PM	#2 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324198	Sounds like low fluid level to me. Possibly a weak pump. Edit: That's going by my experience with much older auto trannys. Could be a lot of other things with a TCM-controlled transmission. With the proper OBD/CAN software, you can monitor/log transmission parameters to get a better idea of what's going on. GZ3 likes this. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma Last edited by SouthArk370Z; 06-17-2015 at 12:37 PM.

06-17-2015, 02:09 PM	#3 (permalink)
kenchan A True Z Fanatic Join Date: Aug 2009 Location: N/A Posts: 76,801 Drives: N/A Rep Power: 141521	please elaborate more on the "ruumm" sound. gbrettin and Amj2020 like this.

06-17-2015, 02:18 PM	#4 (permalink)
vtec to vvel A True Z Fanatic Join Date: Feb 2015 Location: 813 Posts: 3,915 Drives: 13 Z Rep Power: 502909	most likely downshifted twice to a lower gear (ie downshift once to a lower gear (first rumm), and then downshifted once again to another lower gear (second rumm). its possible depending on the speed/gear your car was in at time of WOT. UNKNOWN_370, GZ3 and Jordo! like this. __________________ Don't like what I post? Too bad. I really don't give a sh!t

06-17-2015, 03:36 PM	#9 (permalink)
critical A True Z Fanatic Join Date: Oct 2012 Location: Washington Posts: 1,252 Drives: 09' 370z 7AT Rep Power: 16	how do you know what gear you're in? you're in D. it's probably just downshifting, then realizing it needs to go to a lower gear. doesn't really sound like a problem Jordo! and FPenvy like this. __________________ Quaife w/ gears \|Stillen Gen 3\|SOLD FI Resonated Test Pipes \|SOLD FI 18'' \| 25row Stillen Race \| Progress 35mm/25mm sways \| Swifts/Koni\|Volk G25's\| Stoptech SS lines\|\|SPL Front/Rear Arms\|

06-17-2015, 03:55 PM	#14 (permalink)
6spd A True Z Fanatic Join Date: Aug 2009 Location: South Florida Posts: 3,001 Drives: Q50RS Rep Power: 25	Some one say rum? GZ3, gbrettin, FPenvy and 1 others like this. __________________ -Jay- jonathanjamesphotographer.com

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