Chan Kim

Hello I have done a lot of research and seems like I cannot find the answer. I have a 2005 350z Enthusiast, it's stock, has a little over 70,000 miles. So for the winter break I decided to go on a little road trip ad went to the Grand Canyon I stayed at Williams, AZ. It was very very very cold, the transmission felt really sluggish and I don't know how to explain it but like really stiff upon starting it up in the morning and then I took time to warm it up then it was fine. Also the car was like about to turn off when I wasn't pressing the clutch pedal first couple minutes of turning it on. As I was coming home the clutch began to feel sluggish so I did some research and did my clutch fluid. And then the transmission, something feels really weird it does not feel like how it was before, because before there was little more weight in it when I was changing gears but now it's so light and it's making a little weird spinning noise noise when im trying to downshift. What do you guys think I should do? Thank you.

PracticeDrifter

Winter seems to bring out the worst in my car, especially the transmission.

When it is cold here (minus 3 degress F yesterday) the transmission is so sluggish it almost won't go into reverse. After driving a while it will loosen up. If the car is left in a warm garage, it will then shift fine while it is warm. I thought a transmission oil service magically fixed my car, just to find out it was only the fact the oil they put in was WARM that it helped at all. The next day the issue came back.

So try that. See if your car acts differently when warm.

I used to have mornings where not only was the transmission stiff from the cold, but the clutch engagement point had moved. After getting the RJM adjustable clutch pedal bracket, I was able to adjust the clutch point on a cold day to where it worked again. Now it is still sluggish when its below freezing, but I can still shift.

In a suddenly warm car, or the first warm day, your transmission will feel different. Downshifts especially will be tricky because the timing and points will have moved a bit. If your downshifts seem wrong, then try to carefully rev-match them. If this cannot be done and the issue persists, something sinister is going on.

Also, be careful of transmission oil swaps. A thinner oil may seem to fix your cold-day issues, but will then not be thick enough to do the job on a warm day. If you go into an auto supply store complaining about thick sluggish shifts, they will be tempted to offer you something that is too thin for this transmission.

Chan Kim

The temperature in Williams was -10 degrees F at 10pm so I wonder what it was while I was sleeping. Well I'm back in LA now temperature is around 60s-70s lowest will be like 40s. But the transmission still doesn't feel like how it was before I went on the trip. So should I give it a couple more days? I came back in town last Wednesday. OR should I change the tranny fluid? And for the fluid I'm thinking about Redline mt-85.
Thank you so much for the help, I was really worried that the cold weather killed the transmission or something since its never been somewhere that cold.

PracticeDrifter

Yes, I would go back to something very close to the recommended fluid weight, if you don't have something like that now.

There may be something else wrong, but the sluggish shifts should go away when your car is warm again.