riguyforfly
New member
- Joined
- Nov 18, 2020
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Hi all. After a long search and much back and forth with my better half, we came to the determination that a QX56/80 would be a good mix of what we wanted. It was a losing battle, as my lovely wife grew up in Japan and her father was in the the auto industry there. No matter, a qx56 will be reliable and well equipped, was the thinking. After a while of searching we found a "great" option. A 2011 QX56 that we would name Moby. All recalls done, 145k miles (higher than I would like but an attempt to save the $ toward the car I actually want), good history, and all service history at the local Infiniti dealer. We brought it home and for 2 weeks we had no issues. Took it on a mild off-road adventure to watch the most recent comet. Comfortable, capable, and surprisingly doesn't feel quite as big as it surely is. And then....
While driving home from an errand it first made a hesitant shift (initial thought), with a high rev period, then back to normal. Started investigating transmission and torque converter issues, however nothing showed over the next two weeks. Then while driving around the neighborhood for two weeks it threw and error code and wouldn't rev past 2500 rpm. A quick scan later showed a p0011 code. Having an issue with my car is one thing, having an issue with my wife's car is the seven circle of hell. Thankfully covid had already changed work to "from home" status and our travels were limited.
After becoming friends with the factory service manual, multiple diagnoses, and a few false starts on getting the right parts a friend and I began the process of replacing both VVT solenoids. Things went smoothly, right up until removing the fan shroud. While I thought I had properly moved things "to the position without the hindrance," however after a final quicker movement than intended the fan shroud came out...and so did the end of the reservoir pipe connector on the radiator. Yay, new radiator time! Two weeks later I have a new radiator, and out of sheer I don't want to do this again, I replaced both VVT solenoids, belt, oil. Started up....still rev limiting, but after clearing the error codes it beautifully ran like it should. Cam data looks good, all diagnostics, minus an interior temperature sensor, working as expected.
Fast forward four weeks. Driving 3 minutes from our home it began running rough and the check engine light came on. Based on the vibrations, a scan showed my suspicions, misfire....but the worst kind, p0300, multiple cylinder misfires. I knew it was far past time for new spark plugs, the local Infiniti dealer had told me as much during an initial inspection prior to our purchase. Happily, spark plug replacement on the VK56 was easily done. Cleared the codes, started it up and it drove perfectly.
Cautiously we began driving it not far from home and soon took it on an hour drive to visit some family. All was well on the way there but on the way home on the freeway it began to run rough and the check engine light came on again. Forty five minutes from home and luckily not far from the local Infiniti dealer we waited at a parking lot near a very large oil refinery for the tow truck to arrive. I figured that it was time to have the dealer take a full look. A day later they called me and quoted me $900 to replace the low-pressure fuel pump, as it was reading low. They also mentioned that if that didn't work they would then replace the high-pressure fuel pump and then the injectors, which the then quoted me equally fun numbers.
Though I thought I had been at the point where I throw my wallet and my pride to the dealer, I read up on the procedure and discovered that with an interior access hatch the fuel pump would be an easy fix. I was able to find an OEM pump for a little less than $300 and was able to do the full replacement in just over an hour. Easiest fuel pump replacement I have ever done. Again I cleared the codes and went through the verification procedure and everything checked out. Everything was great and we went back too normal operations.
Three weeks later, all packed up to head to grandmas...much to my extreme irritation, the rumbling started just a half mile from our home (thankfully) and soon a check engine light. Codes revealed a verified P0090 and a pending verification p0087, p0011 and p0021 (those last two hurt). More fuel pressure issues, and a high pressure fuel pump is a high price item. In retrospect, and despite multiple checks through the diagnosis procedures by myself and the dealer. I now believe the following:
What is next:
Other than that we really like the QX56. I would love to get it sorted and back to being the family ride. I had plans to modify the suspension for a little more off road friendliness (those 22's look good but the ride more harsh than I care for)
While driving home from an errand it first made a hesitant shift (initial thought), with a high rev period, then back to normal. Started investigating transmission and torque converter issues, however nothing showed over the next two weeks. Then while driving around the neighborhood for two weeks it threw and error code and wouldn't rev past 2500 rpm. A quick scan later showed a p0011 code. Having an issue with my car is one thing, having an issue with my wife's car is the seven circle of hell. Thankfully covid had already changed work to "from home" status and our travels were limited.
After becoming friends with the factory service manual, multiple diagnoses, and a few false starts on getting the right parts a friend and I began the process of replacing both VVT solenoids. Things went smoothly, right up until removing the fan shroud. While I thought I had properly moved things "to the position without the hindrance," however after a final quicker movement than intended the fan shroud came out...and so did the end of the reservoir pipe connector on the radiator. Yay, new radiator time! Two weeks later I have a new radiator, and out of sheer I don't want to do this again, I replaced both VVT solenoids, belt, oil. Started up....still rev limiting, but after clearing the error codes it beautifully ran like it should. Cam data looks good, all diagnostics, minus an interior temperature sensor, working as expected.
Fast forward four weeks. Driving 3 minutes from our home it began running rough and the check engine light came on. Based on the vibrations, a scan showed my suspicions, misfire....but the worst kind, p0300, multiple cylinder misfires. I knew it was far past time for new spark plugs, the local Infiniti dealer had told me as much during an initial inspection prior to our purchase. Happily, spark plug replacement on the VK56 was easily done. Cleared the codes, started it up and it drove perfectly.
Cautiously we began driving it not far from home and soon took it on an hour drive to visit some family. All was well on the way there but on the way home on the freeway it began to run rough and the check engine light came on again. Forty five minutes from home and luckily not far from the local Infiniti dealer we waited at a parking lot near a very large oil refinery for the tow truck to arrive. I figured that it was time to have the dealer take a full look. A day later they called me and quoted me $900 to replace the low-pressure fuel pump, as it was reading low. They also mentioned that if that didn't work they would then replace the high-pressure fuel pump and then the injectors, which the then quoted me equally fun numbers.
Though I thought I had been at the point where I throw my wallet and my pride to the dealer, I read up on the procedure and discovered that with an interior access hatch the fuel pump would be an easy fix. I was able to find an OEM pump for a little less than $300 and was able to do the full replacement in just over an hour. Easiest fuel pump replacement I have ever done. Again I cleared the codes and went through the verification procedure and everything checked out. Everything was great and we went back too normal operations.
Three weeks later, all packed up to head to grandmas...much to my extreme irritation, the rumbling started just a half mile from our home (thankfully) and soon a check engine light. Codes revealed a verified P0090 and a pending verification p0087, p0011 and p0021 (those last two hurt). More fuel pressure issues, and a high pressure fuel pump is a high price item. In retrospect, and despite multiple checks through the diagnosis procedures by myself and the dealer. I now believe the following:
- Moby hates me
- That whole "the position without the hindrance" bit, I should really go above and beyond there
- I believe fuel issues may have been there from the beginning, possible the root cause of the initial p0011
- Spark plugs really needed to be replaced
- I don't want to go further down the path of replace the entire fuel system as those parts get expensive only to find that my root issue is still present
What is next:
- Need better Scan tool, thinking about an Autel
- Step through each diagnostic step again
- Check out the O2 sensors
- Fuel system treatment (marginal chance of that being truly successful)
Other than that we really like the QX56. I would love to get it sorted and back to being the family ride. I had plans to modify the suspension for a little more off road friendliness (those 22's look good but the ride more harsh than I care for)
