jscho5

This past Thursday I went to my first ever track day at Willow Springs Raceway. The car felt great for 3-4 laps then the car started shifting into higher gears while I was in Manual mode and started to feel sluggish. I would then pull into the pit and end my session with only 3-4 laps. I have no clue what could be causing that. Thankfully I have no issues with it driving on the streets.

Lt8Che

iTrader: (6)

Do you have a transmission cooler? The fluid may be heating up and causing the degradation.


Also, depending on how often you track and mileage, you may need a fluid refresh.

jscho5

I do not have a transmission cooler, but it didn't seem that the oil was getting too hot. Plus it didn't go into "limp mode"

Kris9884

iTrader: (3)

I would also point directly to transmission temperatures. Grab a trans cooler of some kind and I would say since the fluid has already been over heated to go ahead and do a flush. Depending on the miles of your filter you should be fine with just a flush.

Also, Limp Mode is for engine temps, not trans temps. Your transmission will implode itself far before the car even knows about it. Your engine oil and trans oil are going to be very different temperatures and the oil/engine temp gauge has no idea what temp your trans is at.

the walrus

Yep, trans fluid is likely old and getting too hot. Do a proper flush (not just a drain and refill) and it will do better.

+1 on the trans cooler if you plan on doing more track days. They can be very simple to install.

HoldmyMouse

I thought the proper way is to drain and refill x2 instead of flush?

the walrus

The auto trans is full of nooks and crannies, and while a drain and refill x2 would be better than just doing it once, it will still leave a fair amount of old fluid inside.

A proper flush at a shop will push all of the old fluid out and replace with new.

Justin

Epiphany

Drain and fill with some driving in between will avoid old fluid being stuck in the crannies and if you can DIY would probably save hundreds.

afar1

jscho5, your coupe does have the ATF cooler; it's on the driver side of the radiator; check it out on the FSM, under TM, page 261:

2012 Infiniti G37 Coupe FSM - Factory Service Manual

The problem is not your ATF or ATF temp.

I encountered the same exact problem with my AT 2014 Q60 IPL last year at the Fontana Speedway when it was bone stock. I was running it manual, and like your experience, after a few laps, it started to shift to higher gears on its own, around 5500-6000 RPM, trying to cool itself. Disappointed but thankful that the "safe mode" saved the engine from major damage, I searched multiple forums and came across this helpful article:

Project Infiniti G37 Oil Cooler Installation Part I

I installed a 25 row engine oil cooler and the Gen 3 CAI, took the front grill and under engine plastic cover off, and voila, it worked beautifully! According to my temp gauge, I saw the highest engine oil and AFT temp's at 240F, ambient temp around 80F. The engine let me redline, downshift, and rev match at those high temp's, no safe mode. The transmission was responding just fine.

I also followed the G37 project recommendation and installed the Kevlar SS brake lines and switched the brake fluid to Motul 600 RBF, with OEM Akebono pads and slotted rotors. With this set up, braking was very confident without much rev matching needed before the turns, so that also kept the engine cool. The brakes did not heat up.

Make sure you read all the G37 project sections, if you wanna track your car and drive it daily, as well, which is the goal of the G37 project authors.

Have fun tracking!

Elco

Both my EU spec G37 came with OEM engine oil cooler, beside the transmission cooler and steering fluid cooler.
Never had any temp problems, no matter how hard i drive.
Anyone tried to add the OEM coolers to US sped G37?
I am sure will be way cheaper than aftermarket solutions

Kris9884

iTrader: (3)

Suhhhweeettttt, happen to have any part numbers?? I would love Nissan coolers, although I am sure they are fairly small they are still better than no cooler at all.

afar1

The US version have the trans and power steering (that little radiator that's in front of the cooler radiator on the passenger side, you can see it through the front bumper bottom grill). Not 100% sure, but the OEM oil engine cooler may be too small for track use; it's probably 19 rows. A minimum of 25 rows for track/daily is recommended, 34 rows for track-only drivers. My core is setrab. I'd recommend getting a thermostatic sandwich adapter. I got the Mocal, opening @ 165 deg F.

PNW_IPL

iTrader: (5)

Wow the misinformation at the beginning. OP hope the oil cooler does the trick.

Kris9884

iTrader: (3)

Elaborate?

If it's pointed at me, there's nothing incorrect, but its possible that may not be the answer to this problem. Hard to say.

PNW_IPL

iTrader: (5)

That the trans was the issue