Engine Ping on 91 Octane

WhiskeyHotel

I'm really surprised the ECU lets any detonation occur - at least that's audible. I figured it would just back off the timing.

Modshack

It should...Could be a malfunctioning Knock Sensor..

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Rocketman

Thanks for all the input guys. I made an appointment for this Saturday to have the car checked out again. I figure I'll give the dealership that I bought the car from one more chance. I will insist on them running some diagnostics and see if they cant figure it out. If I'm not satisfied I'll go elsewhere. As for the noise, I have not ruled out the heat shield yet but I find it unlikely given that running an octane booster greatly diminished the metallic noise. This could always be the placebo effect but I pretty certain this is the case.

I'll try to keep you guys updated if I find out any new information. In the mean time feel free to chime in if you can think of any more causes or are experiencing the same issue. I would like to hear some input from some of our AZ members to see if they are experiencing the same thing. I know AZ is prone to running different blends of gasoline through out the year to cut down on emissions. I am curious if this could be the cause.

kannibul

In reference to different blends of gas - that happens everywhere, AFIAK.

Around here, we have a "winter" blend, that runs poorly in my motorcycle, and a blend that is used the rest of the year. I try and fill my tank around this time of year with stations that aren't as busy as others, in the hopes they still have the good stuff. Then in spring, I hit the stations that are busy in the hopes that they've cycled out the bad stuff.

1slow370

dang it i was gonna throw out bad knock circuit but mod beat me to it. doesn't have to be the sensor could be the harness too. If adding an an octane booster (recommend NOS in the box or the lucas one in the orange bottle) mostly gets rid of it you can either just drive forever to get somewhere with 93 or take it in and have the dealer use the consult3 on it. He confirmed the problem so it's already warranty and your golden.

Edit: until you start getting gasoline blended for -30deg temps don't complain about yearly blends.

Rocketman

Well, this Saturdays appointment was a bust. Drove the car down to the dealership that I bought the car from just to be told by the service manager that they are unable to run diagnostics on the weekend due to the tech support line only being available mon-fri. This would have been nice to have been told when I set up the diagnostics appointment with him in the first place. I walked out pissed and drove directly over to another nissan dealership here in phoenix. The service manager there was very helpful (considering I walked in without an appointment) and had one of his GTR techs go over the car. Unfortunately they were not able to do a full diagnostics check for the same reason as dealer #1 however they did plug into the computer and run some checks. All sensors are functioning normally and the car apparently is not running lean. I set up another appointment for this Friday to have them do a more thorough run-down. I will let you guys know how it goes.

davidyan

There could be some small delay before the knock sensor kicks in. It has to detect a ping before pulling back the timing.