bapestah

For starters I apologize if I use the incorrect terminology to explain the problem, but it's what i've been told the issue was callled. Also, I did search for anything related but came up w/ nothing. If this is a re-post, my b.

Sooooo to make a VERY long story short, I bought my Z in dec. 08 w/ 11,xxx miles and it was in PERFECT condition (ran perfect). During March of 09 I installed a TurboXS Catback and it was running amazing. About 2 weeks afterward I took it for it's first oil change since i had purchased it and replaced the old oil W/ Motul 300v and a K&N filter. 2 days after the oil change i began to notice the problem which is pretty damn complicated to explain, but here goes:

When the car has been sitting off for a period of 3 hours or more it experiences an RPM surge for a short period of time. Basically, I turn the car on, let it warm up for about a minute, then drive off. About 30-60 seconds into driving the exhaust tone changes (gets deeper, sounds worse) and @ 1800-2000 the RPM's get EXTREMELY jumpy. If the car is in neutral and at a dead stop, you can notice the needle bouncing up and down @ 1800. If the car is in gear, as soon as you pass 1800 the whole car begins to buck like a wild bull. No matter the gear, whether it be 1st 3rd or the, the issue occurs yet it is more noticeable in low gears (1st, 2nd.) Now, if the car is in motion, BUT in Neutral, and the RPM's are raised to 1800-2000, NOTHING happens (no buck/surge). If the car is in gear, AND over 2000 RPMS, the bucking does not occur BUT the exhaust tone is way off what it should be and the car still feels... sluggish. Keep in mind the car has never thrown out any codes for engine issues (misfire, overheating, etc.) Oil Temp is not an issue, and engine Temp is also not an issue (gauges are fine while surge is occurring). Now all this happens for about a minute and then the problem is completely gone. RPMS are fine, idle is fine, and the engine/exhaust sound comes back to normal.

So, the first thing I went for was the exhaust. Took off the XS and put on the stock, and the problem still occurred. W/ a stock exhaust i took it to Nissan where absolutely nothing got done. Week after week they looked for solutions but nobody knew anything. The shop foreman had the ***** to blame my foot/driving style for the issue. Anyways since they were clueless they brought in a specific "master" engineer from the people upstairs and even though he did acknowledge the problem, he was no help. Turns out he blaimed the oil I used (Motul 300v) even though I explained to him that I personally knew people using the same oil and filter for a long time w/ no issues. I doubted it myself, but hell he's the expert right? The tech even explained to me that Esther is harmful for the HR engine, and that he suggested I didn't use any synthetic oil at all.... Go figure . So Motul got taken out, Dyno oil was put in. It solved the issue.... for about a week. The Problem came back but less frequently and I had already put the XS exhaust back on. Due to my laziness of removing the exhaust AGAIN, my fear of getting the newly installed TE's scratched, and the fact that it took Nissan 2 whole months to tell me something as simple as engine oil was causing the problem, I refused to take the car back to the dealer for it to sit out 2 more months w/ no solutions.

I've changed the oil twice since then (once to regular Dyno, and the second time to Mobil1) and have noticed that the issue seems to go away with new oil. About a week after use the problem begins to occur again. Still, NO ONE has been able to tell me a logical solution/explanation for wtf is going on w/ my Z.

Anyone up for the task? Thanks for your time/help/input
(Since it's kind of confusing, i included a Vid. of the issue while it is occuring[ sorry for bad cam. quality ] )

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exZilaration

iTrader: (1)

Nice 2 step you got there

lol could be something to do with the oil since you changed it and the problem went away temporarily did you use synthetics the second and third time around?

usa_alex

iTrader: (16)

you said it doesn't do this every time?
maybe you have a loose connector from valves sensor or any other sensor from engine
just my opinion

jace350z

It seems like something electronic. I'm guessing they checked MAF plugs and other sensors..

bapestah

The third time (last) I used Mobil1, but when Nissan changed the oil they used Dyno, and the first time i changed it afterwards i used Dyno again, and the issue came up all 3 times.

As of today it does it every day but only for a certain period of time after startup..... The only time it doesn't do it daily is when the oil has been recently replaced

I thought so too but im almost positive the Dealer checked all sensors.... and im pretty sure if it was, it throw some kind of check engine light...... atleast that's what makes sense

kramykram

iTrader: (135)

i would clean the maf sensors first and work your way around.

midz350

iTrader: (4)

This same sh** happens to my car sometimes. but I have a code (p1078)
I think it maybe a bad tank of gas.

Zian

The reason I am searching this forum right now is because I am having essentially the same issue with my 07. It is bone stock so its not because of some mod...i'm trying out any solutions I can think of. Let me know if you come to any conclusion and I will as well.

bapestah

Atleast im not the only one..... What kind of oil are you using/have used?

warmmilk

iTrader: (5)

mine does the same thing, gonna be taking it to the dealer soon (when they get some weather stripping in). but mine doesn't do it all the time, so imma bet its not gonna do it when its there... and that sucks cause i'm out of warrantee...

Zian

I'm still under warranty and I had the dealer check on it when the issue first cropped up. Because it is intermittent, of COURSE it did not happen at the dealership.

I will say this: When I had the car in Colorado this summer it did not happen at all. It cropped up big time when I came back to California. So if altitude and temperature have an impact (and it seems they do) I'm thinking it has something to do with air/fuel mixture, an 02 sensor or something. That said...I can't seem to figure it out.

As for your question, I did break in on Pennzoil Dino Oil. I then changed to Motul synthetic, and recently used mobil 1 0w-40 due to the rave reviews it recieved on this forum and others.

My biggest fear is that after I had switched to synthetic, when I had the stealership change the oil (only did it once but specifically requested Motul which they SELL) they used dino oil. Too late for a UOA to tell....

Zian

Fuel injectors are another possible source of the problem that comes to mind. Either way...we are not alone.

http://www.e90post.com/forums/showthread.php?p=6010418

Perhaps this weekend I will get under the hood and see what I can do. Wouldn't it be nice if some fuel injector cleaner took care of it?

Z1 Performance

iTrader: (564)

not all codes throw check engine lights - that would be the first thing to do

based on your oil change stories, perhaps your VTC solenoids are gumming up. Easy enough to remove them, clean them with brake cleaner, use new gaskets, and reinstall. Not a common thing, but I have seen it before

Tac-M

iTrader: (17)

This is a VQ35HR specific issue that has not been resolved by anyone for years now. Here is the thread : https://my350z.com/forum/vq35hr/3078...g-warm-up.html

Tac-M

iTrader: (17)

on a positive note, it does not throw codes and goes away in a minute or so. I learned how to deal with it, and no longer pay attention to it.

synthetic 5w30 seems to keep this problem to a minimum. i ran some 10w40 for hot track days , and it would "sputter" significantly more with that oil.

Z1 Performance

iTrader: (564)

lends more insight into what i suggested ^

Im not at all familiar with the differences in the HR versions vs the DE, non revup, but the exhaust note, inability to rev, all are tell tale signs of the cam timing not changing. Would be interesting to have someone do a datalog while the events happen to see what is going on with the cam timing

Tac-M

iTrader: (17)

not all hr motors do it.

it first appeared around 10k miles on a clean , synthetic oil only motor.

it happens "on cue" at specific temperature range

goes away in 1-2 minutes as soon as temperature rises 10 more C.

a custom ecu flash ( forged/uprev) - almost completely solved this.

on 5w30 300v is quick hickup.

on 10w40 300v - " hold on to your chit" violent sputtering !

bapestah

Hhmm.... Funny thing you say that. Theres been a HUGE climate drop down here in SFL (from the constant 90's to constant 60's) and during the past 3 days the car has only sputtered once.

According to what the special tech told me, what was going on in the engine was that the oil i was using (300v) was too thick (while cold before it warmed up) and when it was making it's way through the solenoids that lead to the camshafts not enough oil was being pushed through, causing retarded cam timing. What i dont get is why it's still going on w. either regular Dyno and Synthetic oil...... Unless they are already gummed up and have all that residue from the 300v.......

Z1 Performance

iTrader: (564)

it's dino short for dinosaur

anyway, I can't say one way or the other, but removing the solenoids, inspecting, and cleaning them, is certainly straightforward enough and may reveal the issue. The solenoids are very sensitive to oil weight and oil pressure

Tac-M

iTrader: (17)

i am liking this thread.... first time in years we have a plausible theory .

i know 300v has nothing to do with the problem, because we have many people in the other thread who never used it.


( yes is drink motul for breakfast.... )