It is my understanding that coils and plugs play the biggest role in pinging.

A coolant flush has also helped -- it may help some hot spots on the engine, but beyond that don't ask me why.

 

Don't confuse the Variable Intake Valve Timing with the VIAS. YK2Driver...........has your car ever had the basic idle ign. timing checked and is the idle stable and correct?

 

VIA error could be an issue as well, but it's had to confuse it with intake valve timing. Doesn't the VQ30DE-K have VIAS too?

 

You're absolutely right, I was confusing VVT with the active intake.

But since you didn't want to add any extra information, I'll submit. VVT alters valve timing with RPM.

http://www.streetracersonline.com/ar...amshafts/3.php

 

According to Nissan, the vehicle speed sensor, engine speed sensor (to determine load), and the engine coolant temp sensor are monitored for valve timing.

 

I've done everything you can think of to eliminate the pinging sound around 2k rpm. The only thing that helped was changing the spark plug to a 1 step cooler plug. I don't hear anything anymore, and I'm completely happy w/ the Max again.....

 

Have you noticed any decreases in performance and or gas mileage?

I would at least thought you would experience weaker acceleration.

 

Actually the car feels more responsive now more than ever. You have to understand that the knocking and pinging sound I was experiencing was predetonation and that was robbing my car of performance and hurting my gas mileage. Since I did the spark plug change my car is operating more effeciently therefore my mileage slightly went up......

 

What the heck is "predetonation"??

 

I think he meant to say indirectly that "predetonation" isn't the correct term. It's either preignition or detonation/knock/pinging which are 2 seperate events. What you described here is preignition and isn't what this thread is about. Knock/pinging/detonation is small pockets of unburnt air/fuel that spontaneously combust, which a motor can survive. Preignition is dieseling, essentially, and is deadly to a motor.

 

A colder plug doesn't mean a weaker spark, contrary to popular belief.

 

I think you missed my point so let me reiterate:



1. "Predetonation" is not a correct and generally accept term.

2. Preignition and detonation/knock/ping are two VERY different things and as such are caused by different conditions. This thread concerns the latter.

3. What you described in your post is the former and kills engines VERY quickly.





http://www.germanmotorcars.com/Detonation.htm

 

This is insulting....i mean really......
1. Invalid term.

2. I edited my previous post to define preignition.

3 and 4 are two different names for the same phenomenon.

 

"Detonation" already refers to a particular phenomenon. Predetonation, means "before detonation" and is a misnomer.
Nope. Please read the last sentence that is highlighted in the definition of "detonation".
Preignition is when the air/fuel mix ignites before the spark plug fires, aka dieseling. Please read post #54 in its entirety.
I though i posted the definition and causes of detonation/ping/knock already...

In short, everything i need to say is already in post #54. If you want to discuss this further, please PM me.

 

..............

 

kenshi.........take the hint. Predetonation is NOT a term that is used. As explained above, detonation or pinging is the sound made by the shock wave generated by the uncontrolled "explosion" of the air/fuel mixture. The normal controlled rapid burning of the air/fuel mixture (the combustion) is NEVER referred to as a "detonation", so there isn't a "predetonation". And you do understand that with most engines the normal spark ignition initiates the normal combustion well before the piston has reached the top (TDC) of the compression stroke?

 

I refuse to say any more until you read post #54 thoroughly and repeatedly.

 

Kenshi........You can Google or MSN all your queries. The originator of this particular thread ain't being helped by this.

 

Thanks for explaining it clearly. I now understand the difference between pre-ignition and detonation and the pre-detonation is an "incorrect" term and I was using it interchangeably with pre-ignition. My apologies.

 

I'm not convinced...

 

You've gotta be kidding me. Just because i couldn't dumb it down to your liking doesn't mean i didn't make an honest effort to explain it to you. For the 20th time, post #54 clearly outlined the differences. You refused to read it.



I'll leave this discussion alone. Don't want to get myself into trouble with the moderators. Good day sir...

 

What plugs did you change out to?

 

Do you have an owners manual? It's clearly stated in it, which are hot and which are cold. Probably something with a 6 in it. Read the stickys for further information on it.

5= stock heat
4= hotter
6= colder

www.NGK.com has plenty of information regarding heat ratings of spark plugs. Also the context of the latter part of this thread has some insight as to why some members have seen results using 'colder' plugs.

 

Actually, I always thought a colder plug, pulled more heat from the combustion chamber by having a higher central mass itself. I know when I was using N20 and back when I was supercharged using a step or 2 colder plugs was critical to eliminate hotspots, like an overheated electrode, in the combustion chamber, as the higher cylinder pressures made for a more detonation friendly environment.

I am still shocked that the cooler plug had no ill effects on performance.
I think this will be my next project but it does suck that I just changed these plugs barely 15k miles ago.

 

I used NGK PLFR6A-11. And to reiterate the cooler plug had no ill effects on perfomance..... My father in law is a mechanic and he suggested to go a cooler plug to cure the pinging sound.

http://www.courtesyparts.com/Merchan...Category_Code=

 

Update:

I switched my oil to Castrol Syntec GC 0W-30. I had asked for some opinions on here as far as cutting consumption back since the 30W side is closer to 40W and my previously used Mobil1 5W-30 is much thinner at temperature.

My catch can is usually half full after 500 miles. Tonight at mile 500 of the GC, my catch can is about 1/5 to 1/8 full. I'll keep the dumps in a container just like the other one and see how much I get in 5000 miles.

 

To the original poster. I had the same exact problem, heard all the people saying it was timing chain clatter, or exhaust rattle etc. I know pinging when I hear it. It was getting worse, esp here in GA in the summer. Same as you, more noticeable once warmed up, under light throttle, roughly 1500 to 2000 rpms. I too only use 93 octane, and I changed plugs. No luck.

Finally took it to the dealer. They said it was the MAF. Also that they should clean the throttle body (injectors? not sure), and of course they reset the engine computer.

PROBLEM SOLVED!!! I know there may be many things that cause this, but I am now a happy camper (despite being $585 lighter). She runs like new again. I have a 2000 Maxima, it has 66k miles. Have had 1 ignition coil go bad. Also 2 days after they replaced the MAF, engine light comes on. Still running great. I take her back in, this time they say a bad 02 sensor. Another $220. Sigh. Still, she has been running great again