Noise when accelerating from a dead stop!

That sound is pre-ignition, and you want it to stop asap. Throw a bottle of octane booster in the tank now and see what happens. It definitely won't hurt and might just stop it from happening. Mixing good with bad gas is a less immediate concern.
 
Don't know how I feel about using an octane booster. The fsm says they don't recommend the use of fuel additives.


[video=youtube;2jbcCr2ll3c]http://www.youtube.com/watch?v=2jbcCr2ll3c[/video]
 
go to an auto parts store and pick up an octane booster additive, something like 104+, throw that in and see if it helps, it should if this is what I think... then I'd wait till this tank is pretty low before filling it up again just to not dilute the next good load

---------- Post added at 05:42 PM ---------- Previous post was at 05:41 PM ----------

yeah, missed the last page and these last 2 posts before I replied :)
 
This is the same exact noise I'm having!!!

[video=youtube;XiBzxxvy3FQ]http://www.youtube.com/watch?v=XiBzxxvy3FQ[/video]


My FX is making a spark knock noise. Exactly the same noise his makes. Why would it be spark knocking?

---------- Post added at 05:05 PM ---------- Previous post was at 05:02 PM ----------

Someone else has it here too:

https://www.infinitiscene.com/search/1/?q=11383-Spark-Knock-2010-FX50S

Yea I saw that a few months back when the problem started ...I posted and asked for a update no reply ....I tried stp fuel cleaner but it never went away ...ill try the octane booster and see if it helps.

Sent from my HTC Sensation 4G
 
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Went to the dealer this morning. For some odd reason the noise stopped and it's no longer making it. I'm about out of gas right now so it seems like it was something related to the gas. Guess I really did get a bad tank. I'm just glad everything is sorted out now and running fine. Mechanic test drove it and found no noises. Then handed the wheel over to me to try and replicate it and the noise isn't there anymore. I am now a happy guy :top:

They also fixed my coolant leak!!

And as always Infiniti of Massapequa took care of me. Mechanic is patient and nice with me and didn't treat me like the sound I was hearing was in my head like other dealerships tend to do. Always recommend them to my friends and neighbors. If anyone in the NY area needs a good dealership, ask for Tom when you go in for service.
 
Ughh the spark knocking noise came back once again today. I tried octane booster and no help at all. I heard it under mild acceleration today when I had both windows rolled down. I was going to take it back to the dealer but everytime I go out on the test drive it stops doing it. WTF!!

I read in the instruction manual that says from time to time light spark knocking is normal. What do you guys think?

photo95n.jpg


I kind of refuse to believe thats true....I don't know really
 
Sounds like it might be the heat shields?? Maybe have the dealer readjust them and see if that reduces the noise. idk.

JD mentioned the throttle body cleaning. I just had to have mine done with 33K on the odometer. I would start the car and the RPM dips really low and then the car just died. Tried to restart and would immediately die. third time started right up and no problems after that. Has done that three times in the last month so had the cleaning done and appears to have fixed the problem. Strange the service manuals do not mention throttle body cleaning as part of routine maintenance but my Tech said they would probably add it in the future.
 
Nah can't be the heatshields as I've dealt with this type of noise on another previous ride and it was 100% spark knock. Back then the only way to get rid of it was to clean the engine using a fuel injector cleaning machine because of the carbon buildup in the combustion chamber.

Although I did have the throttle body problem like what you had which prompted me to make this DIY:

https://www.infinitiscene.com/search/1/?q=16090-How-to-Clean-Both-Throttle-Bodies

So that's not the issue :thumpdown.:

---------- Post added at 11:34 AM ---------- Previous post was at 09:58 AM ----------

Made an appointment with the dealer for next week. Just went out on a ride and it's still doing it. I'll try to make a video later
 
Sounds like your area may be putting water in their gas here and there....start trying better gas stations outside your neighborhood? Just a thought.
 
Not a bad idea. I'm out driving right now and it's making no noise wtf! Lol

I may actually just forget about it cause it doesn't do it all the time. Maybe the instruction manual is right about spark knock being normal from time to time....
 
So after thinking the spark knock went away it came back again on Saturday. So I went out and bought some of this after getting recommendations from other people and hearing good reviews:

photo106iq.jpg


Drove the car near empty and added the Chevron Techron at the gas station then filled up with only 12 gallons of gas. I can officially say the noise has been gone for exactly 2 days now! :top: I'm thinking I had some carbon buildup in the combustion area causing the spark knock??? Whatever it was the noise is gone.

---------- Post added at 09:10 PM ---------- Previous post was at 09:09 PM ----------

Edit: I also filled up at a different gas station this time in New Jersey instead of here lol. Maybe these people have been watering the gas down? I was thinking maybe I've been paying for 93 and getting 87? Who knows....
 
Or maybe you got X's pouring water in your gas? ....I think I recall you've dumped 2 girls already this year? :tongue (2): Car outside + breaking up with girls = Car damage.
 
Just want to bump this to let everyone know the problem has been gone for the past couple of months since I last reported after using the Techron fuel additive. Problem still hasn't returned since then so I'm glad.

No wonder alot of car forum guys swear by Chevron Techron. This stuff is great! Funny thing happened a month ago while I was cleaning my throttle bodies outside my neighbor walked up to me and started talking about maintenance and other crap like that since he saw me cleaning my throttle bodies and said, "I know you probably haven't heard of it but there is this stuff called Techron, you should try it out I run it through my car and it does wonders". He told me he was having some slight spark knock and the Techron did the trick. Funny thing is that I just had used the stuff in my FX lol. I see actually Benz and BMW use to recommend the use of this stuff in their motors.

Whatever it did my spark knock is gone. Since then I strictly stick to one gas station only and pump Shell V Power gas.
 
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