Hey all,

I have a 2009 7AT(stock), It is coming up on 90k miles. I only bought the car a few months ago and the local dealership I bought it from f***ed me, which I take responsibility for to an extent. When I did the test drive I did all of my tests on top of driving the car hard to make sure it seemed solid. Well, after a couple weeks of owning it, I had a misfire and some pinging, but no code. Found out my valve cover gaskets were leaking, whatever, no big deal. I get them changed and change the plugs at the time as well because there was some oil leakage from the spark tube seals. She started to run better, but I noticed detonation between 1600-2000 rpms. I know older Infiniti's and Nissan's have had issues with Det, but I have tried absolutely everything at this point to try and fix my issue and I don't know what else to do besides rip it apart and rebuild it or just wait for it to fail. I had a scope done on the head and the local shop I take it too recommended an in-depth induction cleaning alongside some 44k which helped, but didn't fix it. Both sides of the valves have received cleaner. I also took it to Infiniti and they retarded the timing 2 degrees (the software wouldn't let them do anymore than that). All of this has helped, but it still detonates in this range (1st gear) from time to time, and pretty regularly when it is hot. I am going to change all 6 coil packs this weekend in hopes it'll improve it, but really I am looking for advice on what else to do. I don't think running a colder plug will fix it. The only other thing I can think of is take it to optimize the AFR? Maybe a catch can that can limit any oil making it into the combustion chamber? Otherwise I feel out of options.

Any help is really appreciated.

Thanks y'all.

 

Since you dont know the history of the car, it might be a lingering poorly done custom tune in the ECU (perhaps UpRev since they offer a self-tune option). Maybe have the dealer flash the ECU back to stock to make sure?
You could also try asking UpRev directly if they have a record of your ECU serial number - i'm not sure if they do this type of tracking or not.
Just a few random thoughts to come to mind.

 

Agree with @beefychicken as these cars are not prone to random detonation stock, and carbon buildup isn’t likely on our port injected VQ. Perhaps the previous owner had a tune setup for higher octane or E85. Might also make sense to take one of the plugs out and confirm which ones were used.

2009 also had the transmission issue where shifts were a little erratic. The dealer can check for that update as well.

Also, you bought from a dealership and there was no basic warranty?

 

Is this the noise you are hearing?

If it is, this is not detonation but VTC noises.

Good luck

 

I will follow up on these both. I also have a feeling I found a contributor to the issue. So A little back story on the gasket job. I had an emergency half way through (I finished the passenger side, but had to leave half-way through the job, and I had a friend of my uncle (should've known) finish the driver side so it would be running for work the next day. Come to find out when I was changing my coil packs this weekend, the driver side spark tube seal wasn't sat right so 6 had quite a bit of oil in the well. bought another gasket and plug and will most likely just do that side this week. Also, I checked the passenger side seal and go figure, bone dry as it should be.

To answer the warranty, I purchased from a 3rd party dealer, not Infiniti. Definitely a mistake. I trusted myself enough to do a thorough inspection and nothing seemed off. I get what I deserve though. They had a 3 month "basic warranty", but supposedly only the "gaskets touching the head are covered". Even though the valve covers are technically touching the cylinder head, but not? Anyway, after I get that gasket changed I will take it back in and see what the dealer will do about the ECU."

Thanks a bunch for the input y'all. Will update.

 

This sounds pretty similar. I also had a veteran tech (20+ years) at Infiniti try to confirm for me it was Det (for what that is worth I guess). I just worry because I also feel some hesitation when I hear the noise until it gets past that 2k mark. Anything that can be done?