So I was driving my Dad's 2004 G35x back from work, and almost nothing was working properly mechanically. I drive his car often and know that this is not how it works. The temperature has been between 10-25 deg. the past few days. He and I both noticed it had a funny start up, it would bring up the RPM's like normal, and then drop to an almost stall, and then idle normally. Today, when I started it in 15degree weather, it did it again, but ran fine. Then when I left work when it was 25 degrees, all went to hell. The engine started, but instead of coming back to normal idle speed, it kept idling around 250rpm-500rpm. I think it normall idles around 1000. I was reluctant to drive it, but I needed to get home, and on the drive home, the gear shifts were all out of whack. I couldn't get any acceleration out of it. When I would come to a stop, it would idle below normal again, and then shift funny. By funny shifts, I mean really rough change between 1st and 2nd, and at very low RPMs. Almost as if it thinks the rpms are higher than they actually are. Even normal cruising it would slow down more compared to normal because it didn't want to hold its cruising speed.


No warning or check engine lights come on.
At running temperature it still acts the same.
When I rev the motor, fluid can be heard from in front of the driver's seat.
Battery was in good condition.
Car has 83k on it.
Doesn't have trouble starting, its after the car starts, so it doesn't seem like the starter or alternator.
Turning the wheel seems to also bring rpms down significantly, especially in reverse.
No other issues known.

Any ideas? Thanks guys!

My guess was electrical. I'd have the battery and alternator tested.

But it could also be a mechanical issue under the hood. I wouldn't rule that out yet

prolly the intake temp sensor or the throttle body for the low RPMs u can clean those yourself, check here https://g35driver.com/forums/g-spot/...r-problem.html

for the fluid being heard thats mostly a leaking heatercore, check your fluid level, could be a blown head gasket too i think

Two additions. It is not 250rpm, i misread the tach. It was idling around 500-600, still below the norm. Today when I drove it, everything was perfectly fine. Go figure...

Battery could be an issue, it's an '04 with the original batter still, and throttle body sounds like it could be an issue as well because of the mileage on it. Hopefully it won't crap out on me before I can check it out some more.