Problem with High Idling on my Z
 

I have a problem. Ever since the weather has been cold her in Georgia I have been having a problem when my 370Z gets going. Trying to figure out how to explain:
If the weather is cold outside and I first start my 370 up in the morning, the RPM's will not go below 2 or 3K when in Neutral. The RPM are moving as expected while shifting or in gear, but when I stop at a stop sign or red light and have the car in Neutral the RPM's will go up. This usually goes away after the car warms up, but today I drove it for 15 min and it still stayed at 2K RPM when in neutral.

Any suggestions? I am taking it in to the dealership on Friday, but wanted everyone's opinion.


Also, my check engine light has come on twice and both times the computer read out was cylinder misfire.

17K miles currently on car.

Normal for the idle to be higher on a cold start and then settle down.

The CEL codes should be checked out by your dealer. Also, make sure you're using 91+ octane fuel from a reputable gas station.

The idle is still high after 15 min of driving and engine temp is warmed up

I wouldn't think that the high idle and 'random cylinder misfire' codes would be coincidence. I would definitely visit the dealer and let them know of the symptoms. BTW, which dealership do you plan on visiting? Are you in the Atlanta area?

I am in Conyers, bout 25 min from Atlanta.

the high idle is normal when you frist start the car but shouldn't be like that after 15 minutes...do you know what the oil/water temp was when it was still idling at 2k?

Oil temp was around 200.

Visit Regal Nissan in Roswell if at all possible. Speak with Steph Forsythe (Service Manager) in Service. Ask that Eric (tech) be the one to diagnose your issue. Tell them Jeremy with the GT-R, 370Z Nismo sent you. With this combo, you can't go wrong.

Sounds wrong to me. My G also hates the cold but 15 mins is too long...

If your oil temp was at 200 degrees there's no reason you should be idling at 2000rpm, don't let the dealer tell you otherwise...let us know if the dealer comes up with anything.

Sounds like vacuum leak somewhere or idle sensors getting stuck. Take it to your Local dealer. The idle is too high for one, and should of leveled off after a short drive let us know what they find if you take it.

Will do and I'll keep you posted.

:waves.at.nearby.conyers.dude:

Live near you and probably have nearly the same temps as you (garaged). I'm still in break-in period (700 miles in over a month and a half) and I sometimes start it up and let it idle for 2-3 minutes (if my trip is going to be a short one). In those 2-3 minutes, the idling drops down noticeably from crank-up. If you're getting it as much as 15 minutes later, something is definitely wrong somewhere.

Have it checked out and keep us posted.

Good luck !