Bhooper66

So I purchased my 6 speed manual 350z about two months ago upon buying it every seemed to check out. I am a mechanic but I work for cdjr. I don’t know a lot about the 350z platform but I am fairly familiar with the de motor that’s in it. When I first picked up the car I did all of the basic maintenance oil change, transmission fluid, brake job, power steering…etc. But about 2 weeks ago I decided to changed the spark plugs on it . After I was done I started it up and after about 5-10 seconds it started to misfire noticeable(mind you it is fully straight piped).So I shut the car off and checked all the spark plugs. I made sure they were gapped correctly as well as making sure all of the coils were in good condition and they were. Started it up for the second time and no miss fire I drove around for about 20 minutes to make sure and it was fine.


The following week I was taking a road trip about 2 hours away and halfway there going about 80-90 on the highway it started to have a lot of misfires so I pulled off of the highway and when I got to the light at the off ramp and shifted into first my car stalled I tried 2-3 times to start it back up with no luck. So I pushed it across the traffic to a safe place and check all of the coils and battery connections. I also had a battery tester and jump pack with me. The battery read fine and I put the jump pack on. I let it sit for 5 minutes and tried to start it with no luck again. So I took the battery pack off and started making some calls about 10 minutes later I tried again to start it and it started up no problem no misfire. So at this point I drove to where I was going.


It sat for 2 days and then I had to drive another 2 hours back but this time there was no misfire. But it threw a check engine light. So the next day at work I brought it in and scanned it and long story short I got a misfire code and code for a bank 1 and 2 being over advanced in its timing so I looked into it more and on the back left side of the engine there is a camshaft position sensor connecter and it looked like it was rtvd it it’s place! So I ordered a new one and plan to install it. Mind you I’m 20 years old and this is my only car. So I continued to drive it for about a week to work but about 3 days ago I was coming into work and it started to misfire while going about 30 down a side street so I pulled over and it stalled again but this time It started right back up with no delay and was fine. But the next day I was driving in the rain for about 20 minutes then it started making a winding noise for half a second so I let of of the gas and it stopped then I got back on the gas and it made the same noise so I let off the gas again and pushed in the clutch and put it in neutral. But as soon as I let off the clutch the car stalled but I managed to pull over.

I tried cranking it but the only thing I would get is one solid click from the started motor. So I checked the battery again and it was fine tried to jump it and nothing. It’s been in my garage for a day and haven’t gotten a chance to really dive into it. All I know as of right now is it’s reading low on oil and it is pretty dark As well as the cam sensor might not have a full connection. But tonight I will put the new cam sensor connector in. It came in yesterday so obviously that’s where I’m going to start. As well as seeing if the motor is seized or not. I’m going to update it tonight but was wondering if anyone had better knowledge on this problem as well as any suggestions. I will also be attaching some images later on.

terrasmak

iTrader: (8)

When you attach pictures, I would also attach some spaces too.

icer5160

iTrader: (4)

Lot's of things can cause misfires on DE engines. A good place to start which you have already identified is the CAM position sensors. Make sure you ONLY use OEM sensors, this is very important. I'm pretty shocked to hear about the oil level being low, especially after you serviced all the fluids. It's rare, but not unheard of for a 2003 VQ35DE to burn oil. Do you have any signs of oil leaks?

Another item you should check are the coil pack harness connections (since you replaced the spark plugs). It's very easy to get some of these coils and plugs mixed up (disrupting the correct firing order). I doubt this is your issue since the problem appears to be intermittent, but still worth taking a closer look since it's easy and you're already there to replace the CAM sensor. Btw, did you use the OEM spec NGK PLFR5A-11 spark plugs? Where did you source them from? I ask because there have been a lot of counterfeit auto parts being sold online these days (Amazon & Ebay markets), it can be quite difficult to authenticate the parts if you don't see the boxes/parts on a daily basis for comparison.

Another item to check are the VTC solenoids. Usually replacing the CAM sensors and Crank sensors resolve most misfire issues on 350Zs. It's a very common service item now that 350Zs are hitting 150K+ miles.

Good Luck to you! I hope you get it sorted out. That whining/buzzing sound you described is quite alarming, but it could be a simple accessory bearing causing the problem (not the engine itself). I'm thinking alternator, accessory belt idler pulley, or power steering pump. It could also be the clutch throw-out bearing, these are notoriously loud and tend to concern most new owners of 350Zs, have no fear, it is completely normal.
Cheers!
-Icer