TinsleyC

Just wondering if anyone else is experiencing this -

When accelerating, I often see the RPM jump up slightly between shifts, usually when the shift occurs and I am beginning to let off the gas. It seems to happen most when going from 3rd to 4th.

Of course, the typical view of the tach is to see the RPM increase up to the shift point and then the tach drops down to a lower RPM after the shift. What I'm seeing is a steady climb of RPM until the shift point, then a spike of about 300 RPM before the next gear engages. I can hear the engine race a bit and then slow as the next gear engages.

I noticed this occasionally when I got the car and brought it up to the dealership when I had it in for the transmission reprogramming. They said it wasn't repeatable and not a problem.

Again, it's not all the time and seems to be when I'm reducing the throttle. If I keep the throttle in a steady position I don't see this blip. Just not sure if this is a concern, but it seems like it's slipping a bit...

wakeboardr116

iTrader: (6)

You're not really supposed to let off the throttle when you shift in manual mode as I think it can confuse the computer at what rpms to go to.

Keng

I get that sometimes when I have to make turn in a hurry and step on my brake, the gas blips as the gear shifts down. Seems normal to me.

TinsleyC

I'm not shifting manually... it's in auto when this happens.

ozzypriest

iTrader: (2)

same here - especially when I get on the gas, then throttle back right away - it seems the car will go into a neutral clutch position while (a) the ECU figures out what to do or (b) engine goes into a brief protection period. Probably an engine nanny thing.

TinsleyC

Yes, but that's when slowing down, it's the rev matching downshifts. My situation is when accelerating.

wakeboardr116

iTrader: (6)

Oh. Hm... I dunno then.

bingpwr

iTrader: (4)

I think I kinda noticed this today. It sounds like an extra little oomph right before shifting. I think it only happens in DS mode though

rwong410

I have the same issue, I can never replicate the situation when it occurs, seems random to me, happens in regular D mode for me, not just DS mode. I believe it has already been covered here:
https://www.myg37.com/forums/g37-sed...-shifting.html

DEC1

I have had the same thing happen. It's almost like the car is blipping the throttle as it upshifts...which is actually kinda cool..almost a reverse of the throttle blip when downshifting manually. I have had it happen a couple times in the last week but haven't been able to reliably duplicate it.
I would guess, as some of you have, that its a momentary bit of confusion on the part of the engine/tranny communication.
SOmething we should watch though...could indicate an issue and may require a software update in the future.

LightsOut

iTrader: (7)

adding some ground wires can help out.


I noticed the same thing when shifting. you'll have to time your shift if you wanted shift at a certain rpm point.


its really common on autos.

maxtog

Absolutely. It is called "flare" and the transmission should not do that. See this thread: https://www.myg37.com/forums/g37-sed...-shifting.html

I suggest people reporting, discussing, or with information about transmission flare on the G37 7speed AT use the above thread and abandon this one (just so we can follow a single thread).