Car has 70K miles. always run 93 Shell. Ive been noticing quite a bit of pinging in the 2K range, 2nd gear and up, in mild to mid throttle. if i step on it i dont really hear it, but still an issue. No codes, no CEL. Decided to pull the plugs to take a look. The original plugs are showing their age. I only pulled the far right front plug as i wasnt planning on actually changing them right then. Noticed a bit of oil residue on the plug. I'm going to change them, but could this be the cause of my ping issues?



Also, Is this the charcoal canister or something? Is this causing the black residue on the manifold? the rest of the manifold is spotless.

 

That is not the charcoal canister. The canister is located near driverside rear wheel.

 

That is just the vacuum canister for the VIAS system. The charcoal canister is located by the driver's side rear wheel, like cmd26 said. Black residue on the intake manifold may be from leaking valve cover gaskets.

As far as your pinging, the OEM plugs are rated to last 100,000 miles, but I would definitely change them anyway if they are that dirty.

 

Use 93 octane. /thread

 

If you are pinging and want to change the plugs, go one step colder. Worked for me.

 

How are you able to notice pinging? Did you bypass your knock sensor? If not, then it sounds like your KS took a dump.

I don't think the plugs look that bad, but it wouldn't hurt anything to change them.

When I changed the plugs on my 3.5 Altima at around 75k miles I found that the plug well on the right rear cylinder was full of oil. And of course, nobody sells just a plug well seal, I had to buy a whole new valve cover from nissan. I don't know if the bad seal was causing any kind of pinging, but I don't imagine having all that oil in there was helping the plug or coil.

 

Some cars ping when it's hot and especially with lower octane fuel. Others never ping at all. It's a mystery. If he's not using 93, then that's the 1st thing to do if it's hot. If the KS fails, then usually it tells the ecu it's detonating all the time, so timing is retarded.

Knight has the best advice, so far, I just like being a **** lol

 

Plugs that are in good shape will be a light tan color. That plug is in trouble. You either have a coil problem or you are burning oil in that cylinder.

Maybe you have a coil not firing and that is why you think you are having pinging. Is you check engine light on? If not, does the check engine light work? Does it come on when you are about to start the car?

 

gotcha thanks. Guess ill take a look around for signs of leaking when i pull the manifold.

 

may come to that. Thats usually a band aid though.

 

This car does drink some oil. From what i read on the forums i just figured it was normal.

http://forums.maxima.org/5th-generat...k-plugs-3.html

That thread was helpful. good ideas and trial and error.

 

Nissan FSM recommends #6 but also suggests #5 for colder and #7 or hotter if required

 

You might want to do this to your engine bay too...

http://www.streetfire.net/video/washing-and-drying-engine-bay_138890.htm

 

update. Took a gamble with stock NGK's. changed those, the PCV valve and the air filter. Disconnected the battery while i was doing everything, didnt notice any pinging at first, but about 5 miles down the road it was back just as bad as ever.

Leads me to think something in the tune is causing it to lean out. havent cleaned the mass air, but i really hate this guessing game BS.

 

Did you check/change the gaskets at the plenum? Is the black plastic part of the gasket still moist? Or is it crumbly. 9 times out of ten that gasket is in poor shape and no matter how careful you are at torquing the bolts it will cause minute leaks that can cause pinging. There are 5 of those gaskets that can potentially leak. 2 under the lower intake manifold, one between the lower and upper, 1 at the elbow and 1 at the tb. Some people who have used NWP spacers have reported loss in pinging when they removed those gaskets and used rtv sealant for the spacers.
As i said, Nissan FSM says to switch to a colder plug if required. It isn't a band aid.

 

Wouldn't the plugs be pretty white if it was running that lean?

 

The gasket was moist, but moist with oil. When i pulled the PCV it was covered in oil. So hopefully that was the cause. Thanks for the advice. ill peek around some, gotta be something. Plugs are in now, dont plan on spending another 70 bucks on other ones. I'll pull the timing manually if it comes down to that.

 

So i had the infiniti dealer run a diagnostic. They hear it pinging but cant find anything wrong. Figured i could try an top end service to see if that would help, nope. Not a bit of change.

I'm figuring it's gotta be a sensor. I think that because it doesnt ping when the engine is cold. If my understanding it right the car runs on a base map until things get up to temp. Which leads me to think possibly the MAF or o2's are causing it to lean. Any way to test if these sensors are reading properly or not before i continue the guessing games? i really wish the damn ecu would just throw a code. That would save me a lot of hassle.

Side note, The tech kept reiterating that these cars ping like a SOB when there's not enough oil pressure (he told me why but now i forget, something about timing gears). Kept asking if its been low (it hasnt) but the first thing i did when i got the car was put 5w30 synthetic; i habe always used it in all my vehicles. My mom has owned the car the last 10 years, said she never noticing any pinging. Kind of a long shot, but could the synthetic, which tends to be a thiner and lighter than dino, have caused less oil pressure and thus pinging? This could also explain the hot vs cold pinging. Oil is thinner when hot. Hate to waste the oil, but its a cheap $20 gamble vs buying sensors.

 

It doesn't ping when cold b/c it's running richer, I guess.

 

Changed the oil back to conventional last night. It's pinging considerably less, for a minute i thought it might be completely gone, but its still slightly there. Ill try cleaning the MAF and resetting the ecu, but it that doesnt completely cure it then i guess it's time to start pulling some timing.

 

Check out this video, it shows how to diagnose pinging.


Your problem, as far as I can tell by looking at that spark plug, may not be pinging at all. You could possibly have a misfire on that cylinder, due to an improperly seated plug. Which can be either due to improper torqued plug (doesn't apply if plugs are original), or due to a bad gasket. Also, black on the plug indicates a rich condition, not lean.

I copied the following, which has good info in it for you:

Pinging can be anything from a loud knocking noise to a soft tinkling sound that is emitted from the engine. If an engine has a tendency to ping, it usually becomes first audible when operated in the lower rpm range and during acceleration. Pinging tends to fade away with increasing engine revolutions.
What causes pinging?

An engine can ping for many different reasons. Here is a list of the most common causes for pinging starting with the most popular ones.

• Fuel octane rating too low.
• Compression too high. (usually caused by carbon build up inside the combustion chambers)
• Over heating of the engine or just an individual cylinder. (Hot spots)
• Knock detector faulty.
• Ignition timing over advanced due to incorrect setting or erratic ignition due to a worn distributor. Most modern engines no longer have distributors.
• Blocked exhaust, giving a high backpressure. (A significant loss of performance will be noticed)

Note: The tendency to pinging is highest when the engine runs on the ideal air fuel mixture. (14:1) Therefore a mixture problem -running too lean or too rich- will not cause engine to ping. (Hence why it may or may not ping at different outside temps).

That said, your car would ping if you have a malfunctioning knock sensor, but would not ping due to running rich/lean. Is your car stock? Have you checked your timing?
Good luck! And please stop using the "finger poke of doom" guessing approach when it comes to fixing, your oil for example would never have anything to do with this, unless you had no oil in your car but then you would know and it wouldn't be anything like pinging. First thing's first, make sure the car is actually pinging and not just misfiring due to plugs/gasket. Coils usually throw a code, so if it's not actual pinging I would look right at your plugs/gasket. If it IS actual pinging, then check your timing and go from there. Pinging retards your timing, so the easiest thing you can is check that and see if you feel a power loss when you think it's pinging.