Another problem with my 370Z
 

Well this is the third time the car has gone into the shop. First time they said they couldn't figure it out. Second time they replaced a HVAC sensor. I also complained of a slight ticking in the morning for about 30 sec until the car heats up. They told me its an exhaust leak and I don't doubt them...they just don't know where it is coming from.

A little background on this third trip and I am not sure if it has anything to do with what is going on or not. Last sunday the wife and I worked on giving the car a good wash. I decided to use an engine cleaner to clean the engine bay even though it really isn't all that bad. The next day, the wife did some running and drove to work. On the way there, the car started hesitating, idling rough, and even kind of backfiring. I ran out to her work to check it and wondering if somehow water got into the gas, I put in some heet and filled up the gas tank. On the way home she said it was the same and it finally threw a code. It did get a little better when I took it out the next day but it was still hesitant at low rpm. I took it over to my father in law who owns a auto shop and he ran the code...#6 misfire. Seeing as it is still under warranty, I took it back to the dealer. Now it has been there all day friday, the weekend and when I called this afternoon they said they were waiting from a call back from Nissan tech service (the same thing they told me Friday) WTH are they thinking could be wrong? My guess is bad spark plug or coil. :confused:

If some water got in to the air sensor it will give the comp a false reading that will make the comp. react to it the wrong way and cause a miss-fire, also it could be some other sensor as well. Just for the record when this happens dont drive the car hard you will have a miss-fire, baby it to the dealer and take as much weight out as possible, good luck buddy hope its something simple.:p

Thanks! Hopefully it's nothing major, but I am a little nervous about it right now since I am not getting any answer at all. I guess the good thing is, it's under warranty...just hope I am not without it for long.

Ok so the dealership finally called me this afternoon. Told me that it was from low octane/bad gas and that they reprogrammed the ecu. I did have a dumb moment and put 1/2 a tank of 87 in the car before I caught myself. I wasn't sure about that but I guess they are the experts. I was not able to get over to pick the car up until after the service department was closed. On the way home the same hesitation/bad idle "magically" reapeared. I feel like I am getting the run around and they just dont feel like dealing with me. I want to go to another dealer, but I understand that sometimes it takes a few times to get things figured out so I may just let the original dealer figure it out. It is just really frustrating. I guess I will give them a call and see what they have to say.

Dude when i just got my 370z from the dealer that cheap bastard put 87 in it and it ran just fine, i didnt put the pedal down cuz it was new but it ran fine after that all i do is put 93 in it runs like a charm so stop being cheap. You have one car that does deserve 93 in it so treat it good my friend and it will treat you back the same way :tup:

I only put 87 in it and it was on accident. I run 87 in my old ford so it was by habit I hit that button. Probably got 6 or 7 gallons in before I realized it and stopped filling up. Every other time I have used 93 only. It has probably been a good three weeks and two or three fill ups since I put the 87 in it.

did you drench the engine bay with water?

I guess in a word, yes. I had the car running and used a light easy stream of water. I did not use a direct spray, but I am wondering if just introducing water to the engine bay was a bad idea. I have used the same process a couple of times on my old G35 but I guess maybe this is a whole other animal. :facepalm:

If you have access to a scanner, Conferm the Cyl. that is misfiring and then swap that coilpak with another easy-access coilpak. Then rescan to see if the misfire has changed Cyl. This is a good diagnosis a bad coilpak. also be sure there is NO water in the plug area (Pooled up in the hole) good luck

Good idea. I sprayed my engine bay once and filled up the plug area with water and was having the same trouble.. I pulled the plug wires and let it dry out real real good and but it back togather and it ran great again.

Update: I spoke to the dealership yesterday and they said they tested for compression and all cylinders had low compression. They took the cats off and they claim that one of them disintegrated and got sucked into the engine. They have reported their findings to Nissan and are awaiting a reply back, but they expect to be told to replace the engine. Yesterday, I didn't really think about it, but how does something get sucked backwards through the exhaust? I just hope that they are correct and Nissan indeed replaces the motor. I have been told that after they get the go ahead from Nissan it should only be a couple of weeks until I get my car back. If that is the case, I will be happy.