Cant engage gearshift after sitting for two weeks.
 

Hi, first time poster and two month owner of a 2005 G35 Coupe. The previous owner was one of those "just drive it" guys who did little to it other than (thankfully) regular oil changes. The cur runs fine and other than some things he didn't disclose (like the CD changer stuck with CDs and won't work or eject them), I have no problems EXCEPT this. When the car sits for an extended period of time, as it is not a daily driver, it takes forever to get the shifter to engage into gear. The first time that it happened in December I figured that the gear oil was in need of changing after 12 years, being certain that the previous owner never did and I had it done.

Now, two months later, after no shifting problems I had a tough time getting the car into gear as it took like 15 minutes of idling, moving through the gears once they engaged before I could drive it. You could have maybe blamed it on cold weather and slow moving oil through the transmission yet the weather is 76 today! Could it be that the system has air and needs to be bled (the levels are all correct so there is no obvious master cylinder or slave cylinder problems. Any advise on the problem, a solution or course of action is appreciated.

Change the oil, it's sort of typical behavior for a 6MT that is older and showing signs of wear. I bet once it's been driven for a while and the gear oil is up to operating temp it shifts fine yes?

As I read it he said the gear oil has already been changed (end of first paragraph).

Ahh, it didn't make any difference for me either, if the vehicle has sat or if it's cold my first mile or two of shifts are off. Once it's warmed up it's good to go for the rest of the day though.

That helps to know that is a common problem for someone else and not just me. After it gets going and flowing it shifts fine, I just never had a manual tranny that did that, even after sitting for months unless the master cylinder or slave cylinder had gone and the fluid had leaked out.

What did you use for gear oil in the tranny when you changed it? These trannies are very particular about what oil you use. You should only use the Nissan MTF. If you throw some off-the shelf gear oil in the tranny you're bound to have problems eventually on this car. IIRC Nissan oil is a strange viscosity that almost nobody else makes. I believe it's a GL4 75W85.

I will look into that and no I didn't use Nissan gear oil. The thing is that I am sure the original owner never changed it and what was in it was Nissan. If this becomes a chronic problem then I will look into Nissan oil. Thanks for the advice. Just wondering if you have ever experienced this.

Update: I have found the Nissan gear oil and I am ordering it; it seems that others have similar comments who ordered it.

Two month update: Partyman66 had the definitive answer. I switched to the Nissan transmission fluid and there are no problems, cold weather or otherwise. He is right; you really cannot use other companies fluids and expect them to work as well as the fluid designed for the cars. Don't waste money and learn from my situation, go OEM.