This deserves it's own thread because I want as many people to see it as possible. Long story short. Had rough idling in drive, went to the dealer, changed MAF sensor, then did an idle reset, neither worked. Went with advice here and told them to clean the throttle bodies (which they thought wouldn't work) and my car feels like new. No more rough idling and more importantly any tranny lag is gone, no hesitation finding gears or downshift delays whatsoever in city driving, feels like I just gained 50HP. And it feels more responsive on the highway as well. The car feels like a rocket now, I kid you not.

Had a Q50 as a loaner and wasn't crazy about the car but one thing I did like was how smooth the tranny was over the G. My G now feels smoother. I am in complete shock and giddy about how fun my G has become again and how fast it feels.

People can come on here and say the throttle bodies shouldn't fix the tranny lag but this can't be a fluke and it makes sense that most of us started experiencing tranny problems after about 10K and that G37's are known to have the throttle bodies plug up unusually early. It has to be related. Forget CEL resets and software updates and adaptive tranny bugs. None of that worked but this does. I have 30K on the car and learned to live with the finicky transmission but no more.

The down part is you have to do it every couple of years or so to keep it clean but there's a DIY thread that shows how easy it is and takes less than an hour and costs next to nothing. If you're like me and don't feel at all comfortable doing this yourself then I'm sure the dealer or an independent garage will do it for less than $100. My dealer normally charges $180 for the service but charged me $80 because I have a good relationship with them.

The only problem with DIY is you should an idle reset or "relearn" after you clean them which you really can't do yourself AFAIK. Either way I don't mind spending $100 very 2 years if it means my car will become this responsive as a result. Yeah we shouldn't have to do this and the throttle bodies shouldn't get this dirty so quickly but if it make my tranny buttery smooth I'll take what I can get.

 

Correct me if I am wrong, but I believe a idle reset is not necessary if you do not unplug the electrical connection or tubing from the TB. I followed the DIY instructions to a T and did not need a reset and am now enjoying the same increase in Performance as yourself.

 

You could be right but when I said to the dealer that I can do this myself he said you need an idle reset afterwards. If you're right then it's even better for DIYers.

How often have you done this and if only once, did you notice a tranny lag coming back eventually after 10K or so miles?

 

I think you are right on this because when I did cleaned mine I didnt unplug anything and no CEL came on. Only thing that did happen was the high rev at first cold start but that goes away after a few minutes idling.

 

This is interesting. I need to clean my throttle bodies and if what you say is true I will not only get improved idle and performance, but may also get rid of some transmission lag. Hmmm...

 

I have a 2013 x sedan and i've been noticing lag issues. I current have 7k miles on it. I will try this. Thanks!

 

On your previous thread I posted pics of my TB's with 45k mi of gunk! I certainly will clean them at least every 20 -25k or sooner if I feel necessary. I now have 100,350 mi. And she purs like kitten at idle. I had know idea how rewarding it was to DIY my own maintenance on this car would be! I have recently cleaned TB, replaced the spark plugs and sea foamed. I need to replace rear shocks now ( going with OEM) if anyone has a DIY link please let me know. I feel with some good tools, a lot of patience and a little mechanical ability the g37 is perfect For DIY projects!

 

Thank you for posting this Dan! I need to do mine again. I just had the dealer do a 7AT flush and also update the firmware on the TCM module to the latest.

Patrick, if you're going to replace the factory shocks/struts, you may want to look into Koni Yellow's. I priced the factory replacement parts and they were going to cost slightly more than the Koni Yellows. The Koni's are adjustable for damping stiffness and have a bit sportier of a ride.

 

if you mind me asking, what is your milage on your G. I wanted the dealer to do a flush on mine at 35k and was told the fluid is good for the life of the car??

 

oh yeah and great post dan

 

Thanks for the post OP.
Have to clean TB again. Sure noticed an improvement the first time I cleaned the TB.

 

I feel bad for some of the guys on here last year who were really pissed about the tranny and went to the dealer numerous times getting software fixes and other band aid solutions and went even as far as getting rid of the car when there was a relatively minor fix staring them in the face that the dealers should have known about and should have suggested be done. The one underlying theme I remember from the tranny thread was people griping after a year or so of driving the car the tranny started misbehaving and everybody was attributing to this adaptive tranny gimmick. One thing I also remember was how when they got a loaner with low mileage and how the tranny on that was so much better. The throttle bodies getting progressively dirty fits right into it as far as I'm concerned.

And I'm sure Infiniti know this but a recall to replace throttle bodies is much more expensive than just doing software updates and resets and then telling the consumer that's the way the car is designed when all those things don't correct the problem properly.

 

Good info

 

I have 29k on my G and ive a lag, did all the updates like you mentioned ^ but not much change. I am for sure doing this hopefully ill get the same result as you Thanks bro and good luck everyone

 

Why is this a 7AT thing? Same pair of TB's whether 7AT or 6MT, right?