After all the talk about fuel grade and octane numbers and damage to the engine or not, i realized that i should ask this before my Maxima get damaged.

My car, '03 Max Se Auto, has 40k miles. The engine sensor recall and the TSB were done, car runs well, no warning lights, normal power delivery (**with few possible exceptions here and there when "i think" that the car is somewhatg underpowered under 40mph?!!) ....everything looks/feels fine.

Since i bought the car i have put ~17k miles on it. I have ALWAYS used 91 octane. btw, I can't find 92/93 in Northern california. I do not use "no-name" crappy gas. I am putting Mobil 1 10-30 synthec motor oil, every 5k miles.

The problem is that lately (last month or two) now and then i hear some pinging sound from the engine. I am not even sure if it's exactly a "ping". It sounds simular to the valve noises that my old 14 y/o Audi was making but the Audi of course was much louder, especially under acceleration. MY Maxima makes this pinging under different conditions but definetely at lower rpm and NOT necesseraly under heavy acceleration. WHY am i hearing this and what it is???

I am a second owner and i am not sure how the previous owner treated the car, what kind of gas he put and etc.....he had it for about 20k miles. Should i check/replace spark plugs for now?? The problem is not bad yet and i do not hear it everyday but it's there.

Anyone has any ideas? Whare shoudl i start looking or it's something normal?

Thanks in advance!

 

I have done a complete iduction service, replaced my spark plugs, I only run Chevron 91 Premium, and I still get it on occasion, sometimes on hot days with the A/C on and even coasting at 80mph it does it.

Welcome to the club. Not every 5.5 gen Maxima has this problem.

 

And I betcha you hear it more on warm days than cool days, eh?

Now, mind you....pinging -a soft, almost loud ticking sound- is not harmful to the engine...what is bad is detonation or knock which is the symptom of abject pre-ignition -dat's no good. But, your engine is equipped with knock sensors so it should not knock harshly...

It's probably pinging and if you are indeed using the best possible gas ( do try different ones) you may try to fix it by installing spark plugs that are one heat range colder. Colder spark plugs dissipate more of the heat from their tips through to the cylinder heads themselves and quite often that's enough to eliminate pinging and detonation.

This is basic, old-tech engine tuning, BTW....using spark plugs of different heat ranges to optimize timing advance without getting into the space where ping or knocking begins...this is hugely critical in tuning two-strokes & carries over into four-stroke engins as well.

The plugs should be your first step because the second step is to have your timing retarded by one or two degrees by your dealer with the Consult II tool. Th reason why I would prefer to change plugs first is that if you go the route of retarding the timing, your fuel mileage and performance will be slightly reduced.

 

Yup, got the low RPM pinging here too. It's very light and is heard most of the time (for me) coasting down hill from 45mph. Never on acceleration.

 

Just thought I'd let you know that pinging IS detonation. And pinging of any kind is not good for the engine...but there are differeing levels of preignition (aka pinging; detonation). Obviously the little fluttering one isn't as bad as the harsh obvious explosive detonation, but it's the same principal...

Lots of little explosions or several big ones, it's all bad for the engine!

Changing plugs to one step colder is a good idea. I had to do the same in my truck...

 

Thank you all for your replies.

You suggested "cooler" spark plugs. What would you recommend? What brand and model? Where can i find about the spark plug ratings.

I have always used NGK and Bosch in the past (on Audis) but i never paid attention which one is cool/hot. I just knew what i should put in my engine.
For the Maxima....i have no idea what brands and models are the best.
Please help and let me know what should i buy.

Also...the spark plug replacement procedure.... how difficult it is??? I heard before that the dealer charges crazy $$$ for spark plug replacement on MAximas and i am NOT planning to pay him any $. Is it that complicated to be done? What's the trick? Does it require any special tools? Tell me about the whole thing so i don't get surprised.

Thanks again!!!

 

NGK is fine for the 5th Gen, but the exact part number I don't recall. You can do the swap yourself in about an hour or so...

 

Truth be told, I havent even checked my owner's manual on which spark plugs to use, all I can say is that I think they're NGK and if they are, finding a 'cooler' range is simple because it;s the higher number plug.

For instance, if the recommended NGK plug is something like 'BPS6FP', the BPS7FP would be the next colder heat range plug.....that's how NGK does its heat ranging nomenclaturing.

 

Thats a little optomistic, even for a seasoned veteran. Replacing the back plugs in a 3.5L VQ requires removal of the intake manifold.

 

It takes me approx 8 minutes to get everything disassembled (I have a big compressor and all the tools you can fathom), 15-20 minutes to change the plugs themselves, and another 15-20 to put it back together using the proper TQ specs. So far as I can tell, that's under an hour...and I've done it under an hour the past 3 times I've done them (not all my car, obviously). Only the very first time did it take 2 hours, and that was with some serious BS'ing... (on WILLSE's car)

 

I highly suggest anybody curious about knocking, pre-ignition, pinging, detonation, etc. to do some research on the matter to inform yourself. Do some searches on http://www.google.com/ and http://groups.google.com/ and read up any and all sites you find that describe or discuss the matter.

 

And the point is?? I did some look-ups as u suggest and quite frankly, there is little there that has not been discussed here so what's the point?

 

I understand why he posted that. Basically, learn for yourself because you can't truly trust anyone here. You simply don't know if the people posting know what the hell they are talking about or not...like the people that say using regular gas for your 5th Gen is OK. Anyway, I respect the fact that he also wants people to learn for themselves, but I will always pass on what I have learned over the years to make life easier for the average everyday guy driving an above average car

 

I'm good with your comments -thanks for the perspective
galo

 

Interesting that someone else is having this problem. I have a 2003 with 50k miles. I haverun 89 octane on and off for the last 9 months. I do mostly interstate driving and the thing only pings under very light loads. When running down the interstate at 75mph with the cruise set and going up a small hill it will ping. It even does this once in a while with 93 octane. Had the injectors cleaned and knock sensors checked. No one cdan find a problem.

 

I guess it just looks more difficult. Another member took a few hours, mainly because he disassembled the intake manifold from the metal elbow running from the intake manifold to the throttle body and had a hard time lining it back up.

Do you have anytype of write up or specifics on removing the intake manifold? Do you remove the intake as well as the elbow, or do you remove the elbow at the intake? Is the intake manifold a heavy piece or can one person alone pull it out?

 

Before going crazy, try changing the brand of gas. For some reason I ping with premiun Shell ,but never ping with Mobil.