RPM's Jump when slowing down
 

Sorry if this has been discussed before.

I j got my Automatic G w/ sport package about 3 weeks ago with 30 miles (first owner) on it. I've noticed when I let go of the gas instead of a smooth coast the car seems to jerk just ever so slightly and slow down as if I were hitting the breaks.

Today I was going about 40mph and let go of the gas and it slowed down like a normal car would do and the RPMs started to go down, when I get to about20 I get this down shifting/breaking force and the rpms go from about 1.5 up to two and you can hear the egine reving up and then go back down. To me this does not feel normal but I don't want to take it to the dealership and for to them tell me is normal or they can't find anything wrong with it. I would say that the overall coasting of the car feels very strange.

:icon27:

Opinions? FWIW I only put "premium" gas (93 octane I think it is?)

Thats normal. Its just the transmission downshifting. Nothing to worry about

Happens to me sometimes too, usually after I've been playing around in Manual Mode. Perhaps it's just the control computer having a glitch?

When I get Betty's grounding wires, I'll let you know if it fixes it.

Thanks for the reply guys.

Glad I am not the only w/ this "problem". I just thought it was odd since I have never experienced anything like this with any of my previous cars, last one being an 05 Vette.

Bettys grounding wires wont help cuz this is normal. It is the transmission down shifting and using the engine to slow the car (engine braking). If you take it to the dealer they will for sure tell you this is normal.

As much as I didn't want to hear his I figured as much. I am trying to read the wealth of information available here before I ask questions. I appreciate the answers.

I had a similar problem when I first got my G, but I'd only notice it with AC on. When I would slow down the RPM's would jump noticeably and the car would actually lurch forward. This didn't feel like a standard downshift.

Took it to the dealer, they reflashed something (TCM I presume, it was a while ago and I don't want to go looking for the dealer printout). I think around that time I also switched to Esther Oil but I don't think these two are related (it was mainly to stop the valve ticking).

If you can reproduce it, take it to the dealer. Mine wasn't constant but I got lucky on the tech's test drive, he noticed it and they fixed it. I don't have this issue anymore.

this is normal, no worries.

That's just the downshift rev-matching feature right? Its pretty much to make the car feel more like a manual, like if you rev matched a manual tranny on a down shift and you tap the accelerator to up the revs so that the downshift is smoother. But in an automatic, its the opposite and probably makes it a little more jerky compared to a regular automatic downshifting.

usually it happens when u drive downhill, when it happens, use ur right shift paddle and no more problem.

I get that all the time when i'm going downhill at an accelerated speed. I just took a video going downhill with my G. I am using no gas while going downhill. The engine automatically adjusts rpms as the speed increases with no gas.

YouTube - IMG 0179

Sorry for the poor quality video. I was using a iPhone 3GS at the time.

Glad I found this thread...cuz this just happened to me yesterday. It actually happened right after I played with my Paddle shifting lol But glad it's nothing crucial ya!

There is a post on the Sedan Sub forum that has a similar issue with engine breaking which is similar with that I experience. I guess is normal, it's just a weird feeling.

I'll add that it's normal, and I experience it with my 2009 G37x Coupe. At first I was mildly concerned, but now I'm used to it. It is a bit more harsh IMO in "DS" mode as opposed to "D".

Ur Temp. is 47K??
It is so cold over there. lol I get 100F thesedays here.