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Discussion Starter · #1 ·
I have a question for anyone who has a scan tool that can see live data on their QX. I was reviewing data on my scan tool and comparing it with the values in the Service Manual, everything was within limits except a couple of values. I have no DTC for any of these values and the truck runs perfectly, I am just wondering what values everyone else has?

IGN TIMING @ idle: 11 - 14 degrees value in service manual says it should be 1-4 BTDC (I verified that this is actually ok, funny how the service manual says something different)

INT/V TIM (B1) and (B2) @ idle: 40 degrees CA value in service manual says it should be -5 to 5 CA ( I have verified that these values appear after the truck has fully warmed up, before than the values are spot on at -00.5 to 0.00 on bank 2 and bank 1 0.00 holding steady. The values change when the INT/V SOL become active)

INT/V SOL (B1) and (B2) @ idle: 28 - 47.89 duty value in service manual says it should be 0-2% or rather not active at idle ( I have verified that these values start after the truck has fully warmed up )

The testing I have done so far was I removed both of the Solenoids and verified that there is no debris or sludge on it they look perfect. I could only fully take out one and bench test it and it tested fine. Ohms were in spec and it clicked when I applied 12v. I unplugged bank 2 and started the truck it threw a code as expected, but I noticed no change in start-up and idle. I did the same test on Bank 1 but I did notice that startup did take a little longer and the truck sounded like it wanted to stall but recover, but the idle was not rough, but it wasn't as smooth when it was plugged in. When I either one unplugged I noticed the values went back to Service Manuel spec.

What I am leaning towards is replacing the VVT solenoids, but I want to ask has any one else had this problem? What are your values?

What has been done and ruled out
Timing chain was do around 90,000
HP Fuel Pump done at 148,000
Verified Timing chain is/ was done correctly.
No codes
Truck runs perfectly, absolutely no issues.

2011 infiniti QX56
Thanks in advance.
 

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what mileage is on your car currently? what year service manual are you looking at?
did you buy the car brand new or was it used? if used, do you have any maintenance records?


I have no DTC for any of these values and the truck runs perfectly
No codes
Truck runs perfectly, absolutely no issues.
Verified Timing chain is/ was done correctly.

There's an old sayin', "If it ain't broke, don't fix it".

not trying to be disrespectful, just wondering why are you looking for trouble when there is none?

every car is not going to show the same specs. your car is likely an early production run since your car is a 2011-- probably made in 2010, so your car now is 10 years old and with at least 148K on the clock (took that from your stats above) it looks to be in darn good shape according to your numbers.

i dont have a scan tool so dont have a horse in the race....
 

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Discussion Starter · #3 ·
what mileage is on your car currently? what year service manual are you looking at?
did you buy the car brand new or was it used? if used, do you have any maintenance records?







There's an old sayin', "If it ain't broke, don't fix it".

not trying to be disrespectful, just wondering why are you looking for trouble when there is none?

every car is not going to show the same specs. your car is likely an early production run since your car is a 2011-- probably made in 2010, so your car now is 10 years old and with at least 148K on the clock (took that from your stats above) it looks to be in darn good shape according to your numbers.

i dont have a scan tool so dont have a horse in the race....
There's an old sayin', "If it ain't broke, don't fix it". :D You are right!

Your good....I recently did a repair and was checking everything and noticed that things were not adding up, so I was trying to be proactive and address any potential problems that might come out of this. Just trying to keep her right as long as I can. The values just really concerned me, because it deals with the VVT and oil pressures.
Millage on the car is: about 148,000
Service Manual : 2011 QX56 Service Manual from Infiniti
I brought the car used at around 94,748 miles
I have all services records from infiniti on the truck (timing chain was replace a few months after I took ownership of the car.
 

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There's nothing wrong with getting to know your car and staying on top of it. :)

i'm not a mechanic (but did stay at a Holiday Inn Express before :p) but i can see the numbers going out of spec over time, and even differ from what you saw printed in the service manual that was published over 10 years ago.

still, out of curiosity, i can understand you want to see what others have. maybe take it to a 3rd party shop and see if they woudl do that for you as a courtesy.

as an aside, i had a 2012 qx fully loaded with 6 miles on it when i got it in 2012. i had it for 96K miles before I sold it and the ONLY thing I had done was the timing chain recall (car was running fine but did it since the vin fell under the affected vins). never a check engine lamp or any issues. used old school dyno oil for the first 50k then changed to nissans ester oil for the remainder (3 months/3K change interval). RPMS were at 800 when idle and i drove like a scalded cat!. it was my daily driver and I drove it like a rental.
 

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Discussion Starter · #5 ·
Sorry for the late reply had a couple of things going on this weekend.

"still, out of curiosity, i can understand you want to see what others have. maybe take it to a 3rd party shop and see if they woudl do that for you as a courtesy. " -- Just wanted to compare notes since everything I know about this system tells me it should be the same for all of the QX56 11-13, I think the 14- up have cams for the exhaust, so there values maybe different.

This weekend I was able to find out more about this VVT system and how it operates. I did find out that it will not always throw a code, but there could still be something wrong or off spec. Right now the values for my truck when warmed up is showing that the duty cycle for the VVT Solenoid is active at idle (28% to 40%) when it should be at 0%. Those values tell me that the Intake Cam is advance even at idle and it shouldn't be. The solenoid is allowing more oil in the cam then it should. The reason why this is a little concerning is because this can affect gas millage torque, and the power of the truck.

The funny thing is the service manul listed any number of senors that can contribute to this. Like for instance the cam sensors could be working but reading wrong. Which goes to a point you made earlier about the age of the truck. I guess I just want to be proactive and get those things changed out now before they become a big issue in the future...I already had something that I let go that ended up becoming a big problem (HP fuel Pump), so since than I just want to take care of it as soon as I see something is off and right now I think is a perfect time since I don't drive that much anyway since I work from home because of COVID.

If you don't mind me asking when you sold your 2012 did you get another one?

Thanks
 

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many systems on the car will not throw a code right away. sometimes the ecm will monitor a potential issue and not alert right away. if the ecm sees a "stubborn" issue, it will then fire off a code.

the canbus is a computer network where the data flows in series, so as it travels through other components, if a component downstream is faulty, that could also cause a misread. this is rare since there is redundant data checks but just wanted to mention.

ive read the high pressure petrol pump being faulty in a couple of owners over the years, so i can totally understand why you want to "head things off at the pass" if you will.. :)

can these values you see at startup be repeated each time?

I think what you are seeing is mostly an old truck that has some parts that are wearing causing those above normal numbers. but!!! you can always replace these parts if you plan to keep the car for a lengthy period - thus you will get the most use out of the new parts.

i never had paid those values any attention. i had all my maintenance done at infiniti. i had my oil analyzed to check on the wear of the engine. the car got a clean bill of health. mind you i did not have it at the mileage you did, but as i said, i drove that car daily and like a rental (Added a K &N CAI to it).

i was so enamored with this car when i got it that i studied the service manual at length on how it worked. its fascinating the tech thats "behind the scenes" on the car.

i sold "Fatz" (his name I gave him) and got a tesla..
 

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Discussion Starter · #7 ·
many systems on the car will not throw a code right away. sometimes the ecm will monitor a potential issue and not alert right away. if the ecm sees a "stubborn" issue, it will then fire off a code.

the canbus is a computer network where the data flows in series, so as it travels through other components, if a component downstream is faulty, that could also cause a misread. this is rare since there is redundant data checks but just wanted to mention.

ive read the high pressure petrol pump being faulty in a couple of owners over the years, so i can totally understand why you want to "head things off at the pass" if you will.. :)

can these values you see at startup be repeated each time?

I think what you are seeing is mostly an old truck that has some parts that are wearing causing those above normal numbers. but!!! you can always replace these parts if you plan to keep the car for a lengthy period - thus you will get the most use out of the new parts.

i never had paid those values any attention. i had all my maintenance done at infiniti. i had my oil analyzed to check on the wear of the engine. the car got a clean bill of health. mind you i did not have it at the mileage you did, but as i said, i drove that car daily and like a rental (Added a K &N CAI to it).

i was so enamored with this car when i got it that i studied the service manual at length on how it worked. its fascinating the tech thats "behind the scenes" on the car.

i sold "Fatz" (his name I gave him) and got a tesla..



Man a Tesla....I am not mad at you. For me I like the roar of that V8 sound :) , maybe one day....lol.

"can these values you see at startup be repeated each time?" Short answer is yes. The long answer is that when the truck starts the values are in the correct position:
INT/V SOL (B1) and (B2) @ idle: 0% duty and INT/V TIM (B1) and (B2) @ idle: 0.00 (B2) and 0.50(B2) degrees CA value.

When the truck warms ups, the coolant and oil temp are at operating temp is when the values start to change. This is always the same on startup and warm-ups.

I believe there is a sensor (maybe one of my Cams, I will be testing resistance soon on them to see if they are in-spec) that is going bad, but not enough to throw a code. Something is sending a signal to the ecm to duty cycle the Solenoids at idle.
 

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i traded the roooaarrr of the V8 for the ability to go 0-60 in about 3.2 seconds -- never gets old.. :)

how is your idle? mine was at 800 RPM and steady at idle.

seems like you are ahead of the game and i wish i could help you with those values. maybe @primoV8 , who also has a qx80, can chime in. im not sure if he has a scan tool but he is very comfortable with the patrol/qx.
 

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Discussion Starter · #9 ·
i traded the roooaarrr of the V8 for the ability to go 0-60 in about 3.2 seconds -- never gets old.. :)

how is your idle? mine was at 800 RPM and steady at idle.

seems like you are ahead of the game and i wish i could help you with those values. maybe @primoV8 , who also has a qx80, can chime in. im not sure if he has a scan tool but he is very comfortable with the patrol/qx.

Yeah I guess you can't beat that!

My idle is smooth, but I do see fluctuations from time to time, when I hook it up to the scan tool it says my idle rpm is between 753 to 800 generally. It has on a occasion dip to as low as 600, but the truck felt smooth so I didn't think anything of it.

I got around to testing my Cam sensors, the Service Manuel says there should be no resistance @77 degrees. I measured about 1.23 resistance on each Cam sensor between the one and two pin on the sensor. I went to autozone to see if I could pick up a new sensor, but they did not have the one I needed for my truck. The one they had was for a 2011 but in look more like for a 2010, anyway I had the opportunity to test that sensor so I could verify the readings. The readings for the new sensor was 0 ohms of resistance which tells me that my Cam sensors our out of spec. I mean the truck is 10 years old so I guess I should expect that. The question that I guess I need to answer is the out of spec reading causing everything else to be out of spec? I did not test the Crank sensor yet, but if things go the way they are with the Cam sensors then that is probably out spec to. I am still going to inspect it just to be thorough.


Here is my thought from the items I have already tested and things I have read. The VVT has a built in fail-safe, anytime one of the items like CAM sensors or Solenoids don't work or in my case unplugged for testing, the VVT will default to a default setting which is the Solenoids not being activated at all and the Cams not advancing and retarding, which makes testing a little more complicated.
 
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