Hi guys so the problem I'm having is that when ever my car is warmed up and i turn it on the rpms fluctuate going up and then coming down really low (to the point where the car has felt like its going to turn off or has turned off which has happened only twice to me recently.) after which the car idles normally and runs normally. I have taken the car to Nissan many times for other repairs and always told them about this problem (don't worry i have 5 year warranty that is paying for the repairs) and every time i take it in they say that its nothing unusual and say they will look at it. Nissan fixes it and for a few weeks its fine and then starts happening again. I have never had this problem with any other car or when I first got the car. I have also had a trusted mechanic look at the problem and he said its nothing but i still haven't found a 350z owner with this problem. All of my 350z owner friends don't have or ever have had this problem anyone know what it could be? I've tried finding an answer online but still haven't been successful.

Few details:
-2008 350z
-This only occurs when the car is hot never on a cold start
-This started occurring 6 months into owning the car
-No check engine lights are on
-No mods done to engine
-Engine is healthy and well maintained no other problems except this one
-Car has only turned off twice when turned on due to this problem hasn't happened again

(Hi guys i am new to this forum so forgive me if I posted this in the wrong area I have never posted on any forums ever so im still new to this.)

 

Welcome- next time post a question like this in the maintenance and repair section. It sounds like you are new to cars in general, so it's best to include general info like miles and mods on your Z. That'll help attract some answers. You mentioned having this problem resolved "for a few weeks" by the dealership, but then having this SURGING problem return. Why not ask (or check your receipts) what they did to alleviate the problem in the first place? Might have been something as simple as cleaning the MAF, or another induction issue.

Also, many new Z owners are not aware that the sophisticated diagnostic system built into every Z33 can hold codes that may not activate a CEL. They are accessible via a code reader and might give a more definitive answer.

 

miles on the car would help ...

Things that pop in my head would be to clean the MAFs, look into the cam sensors, crank shaft position sensor, and your O2 sensors...

yea, what did nissan do during their time with your car?

 

Hi guys thanks for the info really appreciate it. The miles on the car are 75,678. The mods on the car are a muffler delete nothing else was removed. Nissan has fixed about 5 o2 sensors because they kept going out and now it's been fine and hasn't given me a code again. They also fixed both my cats one time each and on the receipt all it said was like o2 sensor or cat when they fixed those problems. Another bit of info if it helps is it passed smog even with this problem.

 

Ok thanks appreciate the help, I have cleaned the maf sensors with the cleaner for them and will look into those other sensors and tell Nissan about them and I'll ask my mechanic to see if it has any codes. Once again thank you so much for your help appreciate it. If I could post a video I would but I'm not sure how to do that or just post a link to YouTube?

 

post it to youtube or if you have a file sharing/storage site like photobucket will let you save/share videos...

other free things to try might be the throttle body reset and ECU reset.

considering the hot start is the issue you may want to swap out your thermostat seeing that it's relatively easy, inexpensive and at some point in time it'll go out.