Ok, I have searched on this forum and everything I have found does not gice any answers. First question what is pinging in the engine and second how can you fix it. I have and '03 350z Base w/ an injen cold air intake. The last dyno i did said the car runs lean.

Thanks

 

either more fuel, less timing, or a combo. lower ECT's also helps

edit: oh yeah, higher octane too

 

pin·ing, noun
–verb (used without object) 1. to yearn deeply; suffer with longing; long painfully (often fol. by for): to pine for one's home and family.
2. to fail gradually in health or vitality from grief, regret, or longing (often fol. by away): Separated by their families, the lovers pined away.
3. Archaic. to be discontented; fret.
–verb (used with object) 4. Archaic. to suffer grief or regret over.
–noun 5. Archaic. painful longing.

 

with a g. (j/k)

"Knocking (also called knock, detonation or spark knock, pinking in UK English or pinging in US English) in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front. The fuel-air charge is meant to be ignited by the spark plug only, and at a precise time in the piston's stroke cycle. The peak of the combustion process no longer occurs at the optimum moment for the four-stroke cycle. The shock wave creates the characteristic metallic "pinging" sound, and cylinder pressure increases catastrophically. Spark knock can range from inconsequential to completely destructive."

Detonation can be prevented by the use of a fuel with higher octane rating, enriching the fuel/air ratio, reducing peak cylinder pressure by increasing the engine revolutions (e.g., shifting to a lower gear), decreasing the manifold pressure by reducing the throttle opening, or reducing the load on the engine.

Here, read up :

http://en.wikipedia.org/wiki/Engine_knocking

 

can it be heard at WOT with the windows up? or only when driving next to something concrete that can reflect the sound back with the windows down?

 

depends on how bad it is, but yes it CAN

 

It's pretty difficult to get an NA Z to ping. The stock ECU has a very sensitive knock sensor and the fall back on ignition is a rather big step. What gas are you running? Have you done a tune up? How many miles do you have on the car? You might have a clogged injector on one cylinder... But running lean means the stock ECU isn't seeing something right, they always default to running rich.

Really we'd need way more information to diagnose a problem like this.

 

actually there are a lot (well, not a lot, but a selection) of vq35's that ping, from what ive noticed. there is a whole, stickied thread about it somewhere. it seems like a luck of the draw thing and not really based on the gas you buy. not sure what its related to. it seems like if you get that problem, you get it everywhere even driving in low load conditions (obviously not just cruising but light acceleration). theres really nothing you can do at that point though. reset your computer, run good fuel and do the blow-by filter mod, then pray it goes away