i am having a huge issue with my 07 g35. been through 3 mechanics and 3000dollars and its only gotten worse. nissan reset timing chain. tried different throttle bodies. cleaned maf. tested a bunch of stuff but didn't find anything. they quoted me a new stock engine for 17k.

hard to start. idle is erratic. will hold steady then dip then rise then settle then repeats. engine stalls when disengaging the clutch intermittently, more often than not, when slowing down or accelerating quick then quickly disengaging with also cause the stall nearly every time. loss of overall power.

please please please help me

this thread talk about the issue being faulty CPS. are they talking about crankshaft sensors or camshaft sensors? https://my350z.com/forum/maintenance...in-clutch.html

at the beginning my CEL wasn't on but after the 3rd mechanic(nissan) it remained on. im going to try to take it to advanced auto tomorrow to get a code reading.

take note that i never had this issue until my engine began overheating in slow traffic and i had the 1st mechanic(home mechanic) replace the radiator(stillen that i ordered) and fans(a cheap 150$ one he ordered) that nissan said was backfeeding causing problems. replaced with oem 650$ fans

any replies are greatly appreciated as ive been battling this issue for the past 6 months. i plan on going to infiniti of stuart soon but finally typed in the right string of words to find some threads that had solved the issue. i'm by no means a car mechanic, but i work on carbureted motorcycles and im mechanically capable of chaning a sensor and reseting the ecu


from reading other posts i see that it can also possibly be a faulty fuel pump, 02 sensors, vacuum leaks, even bad grounds for the pedal sensors

 

17k for a new engine? Yea I don't believe that.

Look for a reputable mechanic near you and take it there.

 

I smell
Troll.

 

im not making any of this up. i hope not, but it sounds like im going to get as much help here as i did g35driver... i laughed when i heard the guy say 17k cause at that point ill just do an lsx swap

im looking for constructive criticism at the very least. not people trying to bump theyre points. trying to make a thread that'll aid someone in the future..

like i said ill be taking it to a shop. im a college student who doesn't have an endless supply of money or knowledge to keep getting crapped on by 2 supposedly well renowned professional local shops and a home mechanic.. im just trying to do my research before i head in to a new shop with a fat wallet.

if someone ended up leading me in the direction of the issue on this site then i would gladly throw some money your way for your time and knowledge if i think you helped in a big way.

it only took me half a year just to figure out the string of words to search to be able to find people with similar problems.

 

The problem you describe sounds very much like failing camshaft and/or crankshaft sensors. This doesn’t explain the overheating issue though.

There’s a lot of missing information:
1. Mileage on your G35
2. The codes your car has been reporting.
3. Is the overheating problem solved?
4. Does your exhaust appear normal (i.e., Is it white?).

The overheating issue adds some complexity. For example a warped head could cause some of the problems you describe. In that case the engine damage would probably be significant.

Please keep us updated.

--Spike

 

i updated my profile to show my 2007 g 6mt has 83k miles. i bought it brand new. the overheating issue has indeed been solved. i'll get back to you tomorrow on codes and exhaust smoke although i didn't see any at all today when i was filling up the rear tire while letting the engine warm. my air compressor was literally setup 2 feet being the exhaust too but i will confirm again to be sure.

car stalls way easier than it used to so im very hesitant to take it out on the road. typically i'll shift into neutral by blipping the throttle and not using the clutch and that usually keeps me from stalling when slowing down. but sometime if i rev above 3k rpm and let go of the accelerator, rpms will fall straight down and itll die(very seldom does it stall this way though) ill try tomorrow to get codes

i think depending on codes ill probably try replacing the CPSs myself and if that doesn't work ill take it to another shop

as for the whole story on the overheating: i think my fans went out first. so in slow traffic it heated up and there was only one instance(very first time i noticed it over heated) where it was well into the red and spewed out antifreeze. i never needed to watch my oil temp the last 6 years so i honestly couldn't say how long it was in the red, but it was long enough for me to feel a loss of power in acceleration inwhich i immediately realized and pulled over. i'm guessing thats when i got the huge hole in the top of my radiator. i still drove it to class cause its highway driving(did not know about the hole). 2 months later i took it to the home mechanic, Ulf, to fix the overheating and after he replaced with cheap fans he bought, then csf radiator i bought from importpartspro, and a water pump he also bought, it began doing the stalling when clutch disengaged after i received it back.

before i got the overheating fixed, i changed the spark plugs, broke a cam cover bolt and had to take the manifold apart to extract it. i followed the manual meticulously when i did it. i had trouble with the ecu reset so i just took it to Ulf do it once i got it to idle just enough to drive to his shop, but it never stalled, just not smooth idle. which then is when i decided to just leave the car with him to fix the overheating..

i really appreciate it

 

UPDATE: there is no exhaust smoke

i went to advanced auto. codes read:
P0021 Intake (a) camshaft position timing over - advanced (Bank 2)
P0011 " "(Bank 1)

should i replace all 4 sensors(2 on each side if im not mistaken)

looking at sewellparts.com right now and the part #'s are 23731MA and 23731M(one for each side of the engine) @ the g35driver discount price $85.62 x 4 total = $355 +tax.. not bad at all if it fixes the stalling. i hope i got those part #s right

 

I would replace the sensors for sure. They seem to go bad around 80-100k miles, so it's worth a try. Your engine still runs because of the crank sensor, but the cam sensors are also needed to make it run right.

 

I agree with myfirstzcar. I started replacing sensors individually at around 85k (if I remember correctly), and by now have replaced all four. I should have replaced all at once.

 

23731M 23731AL61A
CAMSHAFT POSITION SE
Fitment Notes: LH
Production Dates: 0806-1206 1 $85.54

23731M 23731AL61A
CAMSHAFT POSITION SE
Fitment Notes: LH MTM
Production Dates: 0806-1206 2 $85.54

23731M 23731AL616
CAMSHAFT POSITION SE
Fitment Notes: LH
Production Dates: 1206- 1 $85.54

23731M 23731AL616
CAMSHAFT POSITION SE
Fitment Notes: LH MTM
Production Dates: 1206- 2 $85.54

23731MA 237316J90B
CAMSHAFT POSITION SE
Fitment Notes: RH MTM
Production Dates: 0806-1206 2 $85.54

23731MA 237316J90B
CAMSHAFT POSITION SE
Fitment Notes: RH
Production Dates: 0806-1206 1 $85.54

23731MA 237316J906
SENSOR ASSY MAGNET
Fitment Notes: RH
Production Dates: 1206- 1 $85.54

23731MA 237316J906
SENSOR ASSY MAGNET
Fitment Notes: RH MTM
Production Dates: 1206- 2 $85.54

Looking at sewellparts.com again and trying to figure out if theres a difference between all the variations of both 32721M(23731AL61A & 23731AL616) and 32721MA(237316J90B & 237316J906).. do i needs to pull the ones off my car to see what theyre part numbers are in order to get this right? not really sure which ones to buy

 

If you can test the sensors, do that first. The procedure should be outlined in the FSM. That way, you're not throwing the baby out with the bathwater, so to speak. You'll find video how-to's on Youtube. If the sensor's bad, replace it. If you can't/don't want to test them, at least stick with OEM. Given the problems you're having with the car stalling, I'm almost leaning toward an ECU issue (possible short).

 

thanks ill give that a shot first. i agree that it might be the ECU(ecm?). could be a combination of both for all i know. not sure how to check the ecm(900$ on sewell) for a short so i'm just going to start with checking the sensors first. ill report back soon

 

If you have access to a 2-channel scope, you can check your cam sensors in relation to your crankshaft position sensor (POS) to see if everything's working properly. Below is a Nissan 1.8L engine waveform for a simple comparison. Note they use hall effect sensors. Red is cam, blue is POS.



The relationship between the cam sensor positions in the firing order 1-3-4-2 and the POS waveforms above show a healthy cam sensor (though you'd want to run it for a while to see if any glitches pop up) and a healthy POS. Nissan can do this easily with their CONSULT tool and should have done that before telling you to drop $17K into a new engine (which, by the way would be harder to believe if it weren't for the fact you live in Florida.) The only reason they would have to replace an engine is if it's mechanically damaged (i.e., blew a hole through the block, destroyed the head, etc.). Did they find evidence of mechanical damage or did they just throw their hands in the air and say, "It needs a new engine!"?

The P0021 code points you to cam sensor bank 2, but the P0011 can mean anything from a faulty CPS to dirty oil. According to Nissan:

This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake valve.

The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing control solenoid valve depending on driving status. This makes it possible to control the shut/open timing of the intake valve to increase engine torque in low/mid speed range and output in high-speed range.

The intake valve timing control solenoid valve changes the oil amount and direction of flow through intake valve timing control unit or stops oil flow. The longer pulse width advances valve angle. The shorter pulse width retards valve angle. When ON and OFF pulse widths become equal, the solenoid valve stops oil pressure flow to fix the intake valve angle at the control position.

Based on your symptoms, it seems like you're dealing with an issue affecting your variable valve timing, which makes me think you should pay closer attention to the P0011 code since that can be triggering your P0021 code.

Possible causes for P0011 are:

- Faulty Intake Valve Timing Control Solenoid Valve
- Intake Valve Timing Control Solenoid Valve harness is open or shorted
- Intake Valve Timing Control Solenoid Valve circuit poor electrical connection
- Faulty Camshaft Position Sensor
- Camshaft Position Sensor harness is open or shorted
- Camshaft Position Sensor circuit poor electrical connection
- Faulty Crankshaft Position Sensor (POS)

I'd take this list to the mechanics you forked $3,000 to and ask them if all of these have been checked.

 

great information. nissan did use CONSULT and the 2 channel scope test your talking about and found the spark to be off, or something of the sort. before them i went to dons auto and they decided to try to reset the timing chain cause they thought ulf had replaced the water pump incorrectly resulting in the chain being off. well nissan hooked up the device, found that the spark timing was off or something of the sort, then decided to reset the timing chain. then they found the fans backfeeding and they thought they fixed it after that so they called me right away to pick her up. the CEL was not on when i initially took the car to nissan so they never found any codes. when i got it back from them, i drove off the lot and literally 50 ft away i stall at a red light like usual then the CEL finally came on. i took it back and it literally sat in outside for a week and a half untouched so thats when i went over there and took my car back cause i felt like they were getting confused and disorganized.

this is exactly what the nissan receipt says: "Performed consult diagnostics - no codes retrieved; performed idle air volume relearn-no success; inspected timing, ignition and cam circuits - ok at this time; checked for ecm updates - none found; checked ecm for performance modification - non found; found backfeed to ecm condition when at idle creating engine shutdown; traced circuit and found aftermarket cooling fans backfeeding creating condition; disconnected fans to verify-symptom gone; necessary to remove and replace cooling fans using original equipt nissan; roadtested upon completion-no further action requred; costumer did advise fans removed were purchased non-oem".

i can scrounge up dons auto's summary

really makes me suspect that ecm is shorted or the harness. also, ill add that when i turn my music up from silent, the rpms and idle will fluctuate +-200 rpm as it begins to play..... i have aftermarket infiniti speakers, 2 12" subs and 7" touhscreen.

 

Wow it sounds like you have a right shed there, have you considered writing to the MD of Nissan US explaining in full chronological detail the process you/technicians have gone through as it sounds like one thing after another after another, I appreciate your vehicle is out of warranty but this still doesn't negate them from all of the problems you are encountering including the fact that nobody seems to know what they're doing. $17000 for an engine, get to chuff. I get the impression they haven't a clue and see you as some sort of money box.

 

After coming back to this thread and reading all the posts, why the hell would you spend 3 grand on 3 different mechanics when you know what codes are being thrown?

Not sure your level of automotive competence, but whenever I need work done by a professional, I tell them what I need, I dont make them figure it out, mainly because I dont trust mechanics or dealerships.

You clearly had access to a code scanner, so if the car is running like crap and you have codes, IMO first thing to do is check the codes and them go from there.

You could have saved alot of money doing this.

And as stated before, stick with Nissan parts when you are repairing this.

Good luck!

 

I agree, but it's too late now.

 

squalz thanks a ton for the criticism on my mistakes and -3k$ that i feel ive already learned from. your now competing on jhc's level with most helpful post. your wrong about being able to access codes.. let me elaborate in this post as ill make it clear what exactly happened and how my relationship with nissan of vero beach ended(sry its a slightly jumbled mess)

lets get something straight first. im not a professional mechanic by any means. im a 23 y.o who doesn't have friends or family that are mechanics. i spent the money i got at my last job to buy all sorts of tools. i taught myself from books and forums how to restore motorcycles 3 years ago(having zero prior experience with any engine and never having ever been on a motorcycle, i went out, bought a 400$ motorcycle, learned how to revive it before i rode it) and now i have a small motorcycle shop running out of my garage, as a hobby(i've only worked on carburetors, not fuel injection). electricals are my weakest area so im trying to learn as much as i can right now from you guys. ever since i started wrenching have not stopped wrenching and ive revived well over half a dozen 15-30 y.o bikes that either sat for a few months or for 5 years. all of this is just as a hobby, for fun, on my days off. im just trying to learn about my car before i head back into a shop

I'm not a car mechanic, im a dental ceramcist with a passion for engines, driving, riding, and hauling massive amounts of ***. im trying expand my existing mechanical knowledge outside of carbureted motorcycles.

my car has sat untouched for the past month as ive been collecting money for another shop while studying the issue with you guys. yesterday was the first time i ever checked codes myself on any engine.


this is the furthest ive had to dig for any issue on my car, other than that its been very reliable since the day i bought it in 07, so ive never had much hands on experiance fixing major issues in cars until now. but i have had no problems figuring out how to do full maintenances and replacing differential bushings by myself in my carport so needless to say i am somewhat mechanically inclined. electronics and FI is where it starts getting beyond me

i do all the maintenance myself since 50k. typically i know what i can and can't work on and i know this issue is beyond me but it also seems to be beyond the past 3 mechanics who haven't listened to what i've said about the issue thoroughly; that the issue is very likely electrical becuase it started when ulf put on the cheap *** fans... instead they want me to consider a new engine and that theres possible crankshaft play..

if i knew what i needed don't you think i would have it fixed already? i explained everything to them like i have here(granted i didnt know quite as much as i do now). ive only been studying this issue for the past 5 months. i wrote down on paper how everything went down so i didn't miss anything trying to explain the issue to nissan, and so i showed it to nissan and they tossed it right back at me so professional like saying "i don't need that". ok well bud i've already got the information memorized in my head and i recon you'll need to refer to it(just later to find that he didn't write down exactly what i communicated verbally about the issue). the guy didn't remember that i came in with no CEL and started mixing me up with other costumers cars. anyways, after nissan did all those tests said in the summary, one of the last things they considered to check was crankshaft play. what?(it didnt seem to be strategic in any way to me. OR maybe it is part of their strategy aka strategy to take my money)... i can kind of understand the path that the mechanic was going in though, no codes being thrown at the time so must have figured crankshaft play as that may not throw codes possibly?.

i always take a meticulous, systematic, strategic path when diagnosing a carbureted motorcycle im working on and i appreciate it when you guys help me do so with my car

SO at nissan of vero beach, the codes were not thrown UNTIL I LEFT NISSAN FOR THE FIRST TIME THINKING MY CAR WAS FIXED. my car NEVER THREW CODES for nearly 4 MONTHS WITH THIS STALLING ISSUE. let me explain further:after nissan called me thinking they fixed it after replacing the fans, I drove off the lot, then DROVE THE CAR BACK TO THEM RIGHT AWAY AND TOLD THEM IT STALLED 50ft AWAY FROM THE ENTRANCE OF THE LOT AND NOW CEL LIGHT IS ON. IT LITERALLY SAT OUTSIDE UNTOUCHED FOR 1.5 WEEKS. WHY, I WILL NEVER KNOW. when i went in to talk to the guy, he talked about crankshaft play. and then engine repacements since checking the crankshaft supposedly cost just as much as replacing the engine itself. they never checked codes even though i told the guy the CEL lights on now so i felt they were confused and not interested in dealing with it and that it was a good time to pull it.. am i wrong for doing that and wanting to go to an infiniti shop after they just had 1.5weeks to check codes?

I kind of know what happened to my car, when it happened, and likely how it started and i can explain all that it in full detail to the shops but the past 3 just looked at me like im crazy, and when i try to explain it again, well nissan certainly got lost, cause CODES WERE NOT BEING THROWN JUST LIKE NISSAN STATED IN THEIR SUMMARY THAT I TYPED OUT FOR YOU GUYS TO SEE in my last post. the first two mechanics didn't even believe me at first that this issue was happening. i'd drive alone and it would happen a few times within 30 min. put the mechanic in my car and it doesn't stall all of a sudden even after 30 minutes). finally i just left it at dons and one of the older mechanics took it home for the weekend and then they finally experianced the stalling issue i talked about. if you want to see dons auto's summary i can show you that they FOUND NO CODES as well.


I, myself, ONLY buy oem parts, esp for my car, if not replaced with quality aftermarket like i did with the stillen radiator. i find i have to explain to my friends and costumers that its important replacing parts with oem rather than ebay and non-oe crap to avoid potential headaches... makes me wonder what water pump ulf put in as well

do you see the oem part #'s ive been posting trying to get answers on which one is right? thats me working on buying only OEM parts

i might be retarded but im not stupid. (quote from a movie? felt it was appropriate)

its not like i told ulf to go and buy non oem parts and put them on just to short out my electronics because i felt it would be fun to pay for to fix. so obviously there is a lack of competency to a certain extent on both my parts and mechanics. i would so much rather focus on the task/issue on hand than what is in the past and cant be fixed

so squalz, in the beginning stage of this issue i didn't have a choice but to trust whatever shop i go to because i just wanted it fixed but im no professional car mechanic. i certainly did not know about failing camshaft position sensors then. i learn as i go... the first post it says"it only took me half a year just to figure out the string of words to search to be able to find people with similar problems." - this means just recently(last week) found a ton of information on this stalling out subject. certainly would have helped having that 5 months ago. anyways thats why im spending hours on end researching this subject on the forums before i try to go back into another shop so i have concrete information to give to them of what the issue is.

this should clear up any confusion. did i really need to explain all of that? probably not. but now you guys have the story.

i seriously appeciate the responses zakmartin, spike100, samsniss350z, and myfirstzcar........

and squalz for trying i guess??

i don't think much more needs to be said here as ill just take this information ive gained in the past week about the codes to infiniti and tell them the overall issues and suspicions.

i appreciate your time. ill report back with my findings

 

yup

what exactly does 'MD' stand for? i haven't considered this yet and im interested to know for future reference

 

https://my350z.com/forum/maintenance...s-already.html this is interesting, ended up being the chain tensioner


also, i just talked to a long time(20+years) infiniti mechanic and he has experiance with this issue. a couple times it was the gaskets behind the timing chain cover that had gone bad. said it had thrown the same codes. only cost 30$ for gaskets and 1000$ labor to open up the timing cover and inspect.. doubt this is my issue though cause 2 mechanics have already taken off the timing cover so they would have most likely seen any oil

THESE ARE PICTURES TO SHOW WHAT GASKETS THE MECHANIC WAS TALKING ABOUT. NOT OF MY CAR