Engine Ping on 91 Octane

kannibul

I agree, and I think the manual says something about NOT putting in additives?

j.arnaldo

I think you hit it right on the nose when you mentioned the O2 sensors. Are they ECU-controlled? Then have her hooked up to a Diagnostics Analysis computer; that should tell the tale of the ping. If the stealership can't diagnose it, they're the most deficient and inadequate stealership I've ever heard of! Good luck, dude. BTW, it's a crying shame that you don't have higher octane gas available in your area. Thank God, down here we have 93-octane Texaco with Techron, my only choice, 'xept in an emergency.

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.

RCZ

2500-3000 rpm = heavy vibration from this engine. See if thats specifically when you are hearing it. I dont know if its a rattle thought because you say you are hearing single pings...no mods right?

This is going to be one of those things you need to datalog to see whats happening. If you dont see anything weird in the logs, then look for a mechanical issue. Does it do it when you rev at idle?

Rocketman

No mods, the car is completely stock.

The rattle occurs between 1500 and 3000 rpm. No rattle when reving in neutral or when accelerating hard. It only seems to happen under light throttle. I also payed attention to oil temperatures today as that's really the only thing we have to go by. It appears that it doesn't start to happen until the oil temperature reaches about 210-215F.

Modshack

A rattle and an engine Ping are two different things. Which is it? Or can't you tell?

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Rocketman

Its a real thin metallic sound. The best way I could describe it is the sound that is made when you bog an engine just before stall. Is there a chance that this might be something other than pinging? So far nothing can be found that could be rattling underneath the car. My only thought would then be something internal. I know the transmission in these cars is generally pretty noisy but the sound usually doesn't appear until after the clutch is fully engaged.

370Zsteve

Both valid points

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370Zsteve

Have to put an exclamation point on this...a ping is a very distinct sound, and to these ears anyway most vehicles I've heard pinging sound almost identical, from 4-cylinder to 8-cylinder cars. So, again, you do know a ping when you hear one, right?

And I have to ask, did the techs at the new dealer hear the noise?

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Rocketman

I have to admit, I have never heard a pinging engine in person so i am a bit lacking in knowledge here. After driving the car today the noise definitely sounds more like a rattle. I listened to some youtube clips of pinging engines and it appears like pinging sounds more like someone shaking a spray can. The noise my car is making sounds more like a loose/vibrating heat shield. I crawled under the car again today and thumped around on a bunch of things. I could not find anything that could be rattling. Guess I'm at a bit of a loss here.

When I took the car into the dealership the tech could not hear the noise. I am assuming because the engine was cold by the time he took it for a drive (car sat for about an hour before he got to it). I ended up taking the service manager for a lengthy drive to get the car warm. He heard the noise and diagnosed it as an engine ping although I am not sure I trust his technical backround all that much.

davidyan

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