Thanks in advance for any help on this. 2004 G35. 290K milrs. Just this week something has changed with my RPM while in motion or starting from a stop.

During morning commute with very little traffic on the road, no issues. Evening commute is fine until I get to the same incline each day. Once I get halfway up the hill at 50 - 60 mph, the RPMs stay around 3K. It doesn't seem to change gears. On the downslope, traffic is stop and go. When starting from a stop, it doesn't move until about 3K RPM.

Today, when I got to my exit, I turned the car off to see if that changed anything. Problem seemed to go away immediately, but then started up again after about a minute. Tomorrow morning I expect it to be fine for morning commute and go through the same issue on my commute home in the evening.

Any ideas?

 

What's the transmission fluid level like?

 

Looks good.

Interesting fact... I pulled over today when i noticed the change in RPMs. Turned off my car for a minutes. When I started it back up, the problem seemed to go away.

 

Sounds like something is clogging the pick-up for the pump inside the transmission. When you shut off the car, whatever is in there drops back to the pan. A few minutes of driving it gets sucked up again.