aredd2009

I have an 07 350z AT with 43,000 miles and about 3 months ago my Z began having a sputtering/hesitation issue after cold starts and sometimes even normal starts. After starting the vehicle and giving it light and constant throttle, as soon as the tach hits about 1100 rpm, the engine hesitates/sputters as if the traction control has just kicked in for half a second. At times it is much worse in that during the same conditions the tach will bounce up and down and the car will accelerate/decelerate for about 5 seconds. This only occurs during first gear only and does not occur while revving in neutral.

I have read all 37 pages of the sticky and understand that the consensus is the vdc/oil and possibly an ecm issue but as I've said it has only recently began doing this. My goal is to confirm whether or not this is the same issue as in the sticky or if it could be something different. No CEL by the way.

This car is bone stock except for wheels/tires, I use mobil 0w-40, air filters are clean. took it to a dealer and they could neither replicate the issue (of course) nor could they find any abnormal values when connected to their consult scanner.

I have attached a video link of the issue, unfortunately I haven't been able to record the bouncing tach just the hesitation/lag while lightly accelerating

As you can see in this video, the tach quickly drops after hitting 1100 rpm.

zakmartin

You may want to check your ABS sensors on a scope to see if you're getting a good wave pattern all the way around (if not, it could cause the VDC to kick in). If you haven't already done so, inspect your AT fluid. If it's dark or smells weird, replace it with Nissan OEM ATF. What you really should do is hook the car up to a scope or a scan tool that can record glitches, record a few drive cycles and examine the data for any problems or faults (particularly misfires). Your car just may need a tune-up (plugs, filters, fluids). Don't dump money into it swapping parts until you know what's wrong though; otherwise it can get really expensive.

aredd2009

Ok I will look into that. I've noticed today that it does it mostly on cold startups and the engine has a somewhat rough idle until it is at full operating temp. So I believe it is something to do with the engine when it is under load. Just did a drain and fill about 4000 miles ago and the dealer recently said the tranny fluid is fine. Also checked maf sensors and they look completely clean. I've also noticed that the more humid it is, the worse it is at startup. I'll post a video later of the bouncing tach.

Thank you for the response.

aredd2009

I take that back about it only occurring in first, it happens in all gears. Hooked up a scanner and no issues that stood out to me and ive been monitoring it when the issue occurs. The person I bought the car from did have K&N drop in filters which I recently removed. The issue seemed to actually improve after i removed them. So I tried putting them back in and the problem seemed much worse. So i guess the next thing i will try is cleaning the mafs to remove any oil residue that may exist. I read this on another thread and it seems reassuring

"I have a brand new 2008 Nissan 350Z roadster. At 500 miles I decided to install K&N air filters for that vehicle. After 1,000 miles I reinstalled the OEM air filters. The K&N air filters must have given the engine management computers problems. Acceleration with the K&N filters was very touchy, the engine surged, and a small press of the accelerator would make the vehicle lurch ahead then stumble. I switched back to the OEM filters and everything has returned to normal. I would not recommend K&N filters for use on a 350Z 3.5 liter V6."

zakmartin

K&N is snake oil. You don't get any better gains over paper filters and the oil will foul your MAF sensor. Every time I hear someone say, "don't get an intake, just use some K&N drop-ins" I roll my eyes. You might as well throw in a Turbonator and some Slik-50 while you're at it.

Marc Crowley

i had a similar issue but it was a bit more drastic... check all the vacuum hoses on your engine make sure there tight since they are made of rubber and with the change in temps they will expand and shrink.. making some fastners lose is the cold causing a vacuum leak..also make sure the maf sesnor has the rubber ring around the base of it that will cause a idling issue as well....i thought my hoses were tight i have only 57k miles on mine so first thought to myself of pfft yeah like they are loose..turns out the PCV hose dry rotted and begain to leak a little. also the rear vac line clamp wasnt tight enough.. as soon as i pop out my bad MAF and did that check my engine stoped the hesitation..i still have a slight hesitation but i beilive the main vac line running to the intake has a small leak and im going to check it out this week end...

just thought id share my insight

aredd2009

Thank you for all the responses. So at this point, the weather or temperature makes no difference. The hesitation occurs right when the temp guage reaches normal operating temp. In fact, it drives great when it is cold. It's almost as if it occurs during the transition from cold operation to fully warm operation. After driving for about 1 minute at normal operating temp, it's no longer an issue. The majority of the time, it occurs as shown in the video, but in some occasions it lurches and sputters uncontrollably in all gears during any type of acceleration. I've cleaned both MAF sensors with MAF cleaner, and nothing has changed. The k&n filters have been out for a while and I have stock nissan filters installed.

Next, I'm going to check the plugs, coil packs, and definitely look for vacuum leaks.

Also, the idle can be rough at start up at times, at least not as rough as I remember when I first got it. And the shifts seem a little off to me, but I can't be sure because I havnt driven any other auto z's and the dealer says the shifts are normal.

ickis

iTrader: (1)

not sure if the 07 has the same wiring as 03, but i would check all of your taillight bulbs, make sure all your lights are operating. A burned out bulb, as i have learned after many swapped parts, will cause hesitant accel sputtering.

aredd2009

Are you serious? Can't see how it would be possible, but all my lights work fine. The rear have LEDs so there's no issue there. I also have led turn signals with load resistors but this problem occurred before I replaced the bulbs. I also have led license plate lights but I honestly don't see how that could affect engine acceleration.

Anyways I recently changed all spark plugs with oem densos, swapped around coil packs and nothing has changed. I can also say that when this event occurs my exhaust note changes drastically. The dealer recommended I have an advanced diagnosis but I consider them more of parts replacers and vs true mechanics. The most interesting thing to me is I have no check engine and no registered faults therefore the ECM is not detecting any misfires whatsoever. In fact it didn't even detect a misfire when I unplugged one of the coil packs.

paul7002

I have the same exact problem with my 2007. So when I press the gas pedal slightly it sputters and drops right close to 1100 rpm. I can do it in gear foot on the brake(auto). So this happened to me after cleaning the maf's and throttle bodies. I must have a vac line not right or screwed up a TB some how. I've done the reset and relearn which I couldn't get to work until I recleaned the maf's must have not done it right the first time. Just wanted to share what I've done maybe add a little insight.

The_Assassin

I have the same problem. After a few months with it you wont even notice it anymore. I have a manual so I just stay out of the rpm rand that it acts up in until its gone. I have an 07 btw.

aredd2009

So after doing this, was your issue resolved? I have never messed with the throttle bodies as I have read that it's not something you should do.

I still have had no luck in determine the cause. I've been reading that this could be a much larger scale problem having to do with the continuous variable valve timing when the engine transitions from cold to normal operating temp. Apparently, it happens to a lot of manual hr owners and many of them have given up.

However, When I first got this car it didn't do it, which leads me to believe that it can be fixed. I just need to find the cause.

kham25

iTrader: (3)

Have the same damn problem, I've changed ECM, Throttle Bodies & Maf Sensors. It still Idle surging and bogging down.. 3 Dealers all clueless and no idea what to do. I hate this damn car now so annoying to driver at lower speeds...

aredd2009

I believe I have found the issue. What I ended up doing was switching back to a 5w-30 oil instead of using 0w-30 (german castrol) or 0w-40 (mobil 1). After doing lots of research I learned that both the variable exhaust timing and timing chain tensioner are controlled via oil pressure and viscosity. So perhaps the 0w oils respond differently at certain temps especially when the variable valve timing kicks in around full operating temp. The oil I am using now is called penzoil ultra (5w-30) which is supposed to be a decent synthetic oil compared to German Castrol and mobil 1. Hope this helps. Havnt had one occurrence for about a week now.

Phono

Hi guys, sorry to bump an old thread, but I'm having similar issues. I have a 2004 manual 350z and after owning for 10 months it was due a service. Friend of mine is a mechanic so I asked him to give it a usual service but also change the trans and diff oil (clunking when pulling away so figure can't hurt to change).

I noticed some hesitation a couple of days after in the Low revs and also around 70mph mark. Today when I stated it sounded rough and driving home the engine light started flashing. It was driving like a coil had blown. After sitting on the drive for an hour, started it up and it was okay again?

He put in 10w/40 oil - can oil do this to the z's. Or should I be looking at other culprits like the plugs? I assume if it was the plugs it would be doing it all the time? Just seems strange that the wrong type of oil can make the car react this way? Any advice appreciated.

aredd2009

So just to update, I have continued to run a 5w-30 oil (Pennzoil ultra) and although it has reduced the occurrence of the issue, the problem is still there. I have sort of grown to ignore it as it only occurs for about a minute when the vehicle reaches normal operating temp. I know for a fact that this issue has to do with the variable exhaust timing in some regard. I know this because the exhaust note changes drastically when the issue occurs and I have never once registered any sort of error code. I have replaced all spark plugs, I have cleaned and examined both MAF's, examined valve bodies, I have stock air filters, and I am obsessive when it comes to maintenance. I'd also like to point out that this issue started when the car had only 40,000 miles so the probability of some sort of sensor going bad is just unlikely to me. On other forums, many people with the g35 HR have had the same issue and a few of them have remedied it by doing some sort of ECU update which reconfigures the engine timing which I will look into but my dealer has heard of no such thing (of course). Another member had his g35 at the dealership for two weeks and claimed that the dealer finally fixed it by replacing the valve timing covers which contain magnetic retarders that can sometimes send erroneous signals to the ecu. This member had "word for word" the same exact issue as I have. My next ideas are to just simply try oem Nissan oil and filter and look into an ecu upgrade/reflash.

Here's some links to check out: http://forums.nicoclub.com/engine-he...s-t567594.html

http://forums.nicoclub.com/strange-h....html#p6052624

https://my350z.com/forum/maintenance...g-warm-up.html

jonowijono

Hi , got a similar issue with my 08 HR Auto. Previously had P0014 and P0024. Car would jerk at low rpm once the car is at peak temperature. (jerking only on soft acceleration/gas)

Replaced both the valve timing covers (not cheap ) and the codes disappeared. However now the car jerks more frequently. It would start jerking just after cold starts constantly at low rpm, or from a stop/start.

Driven the car for about 2500km/1 month now and the jerking has been constant. I did notice that when the valve timing covers we installed, they didn't do a valve timing re-learn. Could that be the issue?

Thankssss

zakmartin

Check out this site: https://www.autocodes.com/p0014_nissan.html

They cover the code on the Maxima. Check the service bulletin procedure against your HR and see if they use the same parts. The FSM is located here: http://www.nicoclub.com/manuals/350Z/

You could be getting more oil flow to something gummed up with junk located downwind to the new valve covers and their lovely clean journals. This might explain why the sensors say everything is fine, but the engine's behaving like garbage under load.

GT-86

Any progress/update on this issue.

I have a 07 HR MT with the same issue for the past year. Even happens on downshifts as soon as throttle is applied. Would a engine oil flush additive help before an oil change?