I have an 03 g35 sedan with 150k miles, and recently I've been having what seems to be transmission issues and I was seeing if I could get anyone's input on this.

When I'm going up a hill and the car is losing speed, occasionally when I give the accelerater a good press, the transmission seems to jolt/clunk and then the rpms continue to rise. This seems to happen most when the engine is already running at about 2000 rpms and seems to jolt when I push it up to about 2500, then after the jolt, the rpms rise smoothly and the engine or transmission doesnt seem to be losing any power.
Im not too knowledgeable when it comes to the causes for these kinds of things, so any help would be greatly appreciated.

 

Forgot to mention the most important part, the transmission is automatic.

 

Have you checked your fluid?
Make sure you warm it up to operating temp then check your fluid on level ground.

When was the last time it was flushed?

 

Curious what it can be. Please keep me inform

 

I'm still working on figuring out what's causing this. I'm planning on going to a dealership to get it checked soon (I don't have a dipstick to check it with). The last time it was flushed was at 114k miles, so it's running right within its scheduled transmission flush, so maybe it's time to go get it worked on. I like to do most of the maintenance myself, but this is one of those things I'll let the dealer handle.