pinging and knocking sound from engine? need help
 

The problem has been solved. :)

using "Search" function you can find a bazillion threads on this topic.

If you changed any parts like plugs or coils you might wanna recheck if you installed them correctly, if not get some gas tank water remover and some octane booster to clean out tank.... Also if you never changed your plugs....Change em No codes yet? Egr,misfire etc..

You really need to know what they will be doing for $90, otherwise, you are better off starting with strong dose of fuel injector cleaner and/or combustion cleaner and/or carbon clean treatment etc.

If I were in your shoes, I will find an independent shop which can carbon clean using MotorVac or BG44K chemicals. That service will run you between 100 ~ 200.

If you are enterprising, look up Seafoam and have at it yourself for $10.

In short, save that $90

- Vikas

Thanks, I went to pep boys and the mechanic test drove the car to hear the pinging but unfortunately the engine didnt ping while he was driving. He said there has to be a check engine (SES) light in order for him to do any diagnostic to find the problem. He suggested me to put the octane booster in the tank and which i did and filled the tank with 91 octane gas.. so all i have to do is wait and see if the pinging goes away, if it doesnt then i will have to go for the carbon cleaning service as you suggested. I am surprised that why theres no SES light even though it pings very bad sometime. The sparks plugs were changed 35k ago so i am sure it has nothing to do with plugs. I asked the mechanic to check the timing and he said the timing cant be adjusted on this car cause the timing is automaticaly adjusted by computer.

since HE can't do the timing adjustment then its IMPOSSIBLE to do.....

wow.

First of all they should be able to have a OBD2 plug in to monitor timing(ignition)

Second of all i dont think octane booster isnt going to fix your problem. In most cases issues cant be solved with something in a bottle.

Third of all you should post up a sound clip if you can get one. There are many knowledgeable people on here that maybe able to figure out your problems.

Is the perfomance affected at all?? Do you know how to read plugs by any chance? Those might be able to point you into the right direction.

I dont think performance is affected but who knows maybe it is because of pinging and knocking, I am thinking of going to a different auto shop maybe i will try firestone. Dealers will rip me off so i would stay away from them at the moment. I think something is dirty and needs a cleaning but i am not sure what it is, I can do seafoam but i am afraid that it may not fix a problem. If it couldnt get fixed then i will just have to leve it alone untill i get any codes etc but trust me its quite annoying sound.

If I recall correctly, the manual calls for 92 octane fuel. That said. I had a similar problem with my 2000 Maxima and it was due the engine knock sensor having failed just after the warranty ran out. Didn't matter what octane gas was in it. The engine would ping at anything close to full throttle. The dealer acted like it's a pretty common problem. I'm on my third Maxima (a 2002) and only had the issue with the 2000. All of the VQ engines have the knock sensor that retards spark when the engine first starts to go into pre-ignition (which causes the pinging).

My problem is not the knock sensor, its the gas that i used. I've always used 91 octane cause thats the highest we have in our area, i have tried everywhere to find 93 octane but never succeeded. I added a bottle of techron fuel system cleaner and the pinging has reduced but i have to finish the whole tank and then do the second treatment and will also do the seafoam treatment when time to do the oil change.

I run Sunoco 94 octane in mine and have no pining issues but I have experienced this pinging when I use a steady refueling 91 octane from my local Shell station, I picked up a can of Sea Foam and put 1/3 of the can into a full tank of gas and no longer have any pining when I use the 91 octane ... but I do prefer the 94 octane from Sunoco a few cents more per liter but it sure helps keep things cleaner inside.

we dont have 94 octane here, i never seen 93 either the highest i've seen is 91 at most of the gas stations. I am gonna buy a can of seafoam but shouldnt i put it through the brake booster hose and let the smoke come out? I didnt know you can also put it in the gas tank. I think i will put in the tank cause its easier. Btw what brand/kind of seafoam did you buy? does autozone carry the one you bought?

EDIT: I would also like to know if you always use the seafoam whenever you fill the tank with 91 octane or you just used it once?

putting a can of seafoam in the tank will clean out the injectors, and will also thin out the oil a bit. so after the tank of gas is gone you will want to do an oil change. I noticed you are in California. How's the temp down there? The hotter it gets the more prone you will be to pinging.

Please, explain.

The pinging is normal (especially those with 17* timing), someone explained in detail is another long thread but summary is that the sound comes from the way the injectors fire under light throttle, was fixed in the 04+ Maximas. Therefore learn to live with it :)

I think it goes a little deeper than injector firing but it might not be worth mentioning since there's nothing you can really do about it. :)

Sounds like you need a fuel system flush and a tune up.

It is a product that you might want to use once maybe twice a year, putting a small amount (1/3) of the can into the gas tank on a fill up will help to clean up injectors, sucking 1/3 of the can up by the brake booster hose will help to clean up carbon deposits in the TB or adding 1/3 to the oil crank case to clean out carbon & sludge build ups (and as Knight_yyz has suggested an oil change should follow directly afterward) like you said blow out all that white smoke(carbon & sludge build up) and then head for the oil change as your oil will have become quiet thin. I would imagine autozone should sell the product but I am not in your area so I can't say for sure. I used the liquid version ... not the deep creep spray

Pinging is 95% gone with 2 bottles of techron fuel system cleaner on each fill ups. New air filter also helped reduce pinging. The problem was the mobil 91 octane gas, i have switched to 76 now and hope i dont get pinging again in the future. I bought the seafoam but have not yet added in the tank cause i am gonna wait till its time for oil change. Thanks to all of those who posted in this thread i really appreciate all help.

Seafoam in gas tank has nothing to do with the oil.

I havent decided if i would let it suck thru the brake vaccum hose or would add in the tank. But i might add half in the tank and half thru the brake booster hose if i did that then i would need the oil change i guess.

Just do it right 1/3 1/3 1/3 otherwise what's the point. Oil change will run you $22 which isn't much. I drove about 100 miles after I used seafoam and then changed the oil. You dont need to change the oil immediately, but it isn't a good idea to leave it in there for long.

MAF!!! Ive had this issue for over 6 months and nothing fixed it, Replaced MAF and Everything went away, Feels like a new motor, no ping even with mid grade fuel. Ive had so many people tell me it was the maf even though when i tested it and viewed the data logger it looked ok, but it was weak, Replace it no questions asked, unhook batt, let sit like a hour or 2, install new MAF , hook up batt, start and enjoy.

I did have the maf sensor checked and mechanic said its in great condition. Btw the maf on 5.5gen cost over $400 so i wouldnt wanna spend that much on something which is not even defective. If i had 5th gen maxima i wouldnt worry about replacing the maf cause its only $100. I am gonna do the seafoam and will see how it goes. 90% of the pinging is gone its just the 10% that i have to learn to live with.

I use mobil 1 10w30 and mobil 1 filter so it cost me $55 with labor. I change it on every 6k. I am thinking of going with 10w40 cause that may help eliminate the pinging since the oil is little thicker. I heard its better to use thicker oil in hot weather like california?

I know how you feel...had the same problem with my maxii when i started putting 91 but decided to put 93 and never heard it ever since!!!!!

You can get a 5th gen maf and have someone change over the temp resistor, it's very easy to do.

My moms I35 would ping under light throttle even with stock timing and 93 octane, having it bumped down to 13 or 14 was the only thing that stopped it, haven't noticed any performance loss and mileage is reading 25.4mpg with an average speed of 32, I'd say that's pretty good for an auto that has a lot of metal shavings in the trans fluid and slips ocasionally :wall:

Who adjusted the timing on your moms car? because i think most dealers wont do that without diagnosing the engine. And i was told that timing on new cars is adjusted by computer and cant be adjusted manually? If the 10% of my remaining pinging can solve by timing then i wouldnt mind adjusting it lower to 14.

Trust me i feel ya man, mine tested fine but it was still the problem. it took me 6 months to finally accept it.

My car only has 100k. And btw the pinging is only 5% now and i am sure with one more bottle of techron fuel cleaner it will completely disappear. :) i am happy!

I35s leave the factory with 14 vs Maxima with 15.

Some maximas have been found with 14* base timing from the factory.


I was very hesitant to bring this up because there's really nothing anyone can do about it but the true root cause of this pinging is poor head design. There's less swirl flow vs. 3.0 heads. This is the MAIN reason the compression ratio was raised from 10.0:1 to 10.3:1; to increase the speed of flame front travel to try to work around this (credit: nissan SAE technical document). It wasn't done for power. Less swirl flow = less homogeneous mixture of the a/f mix. Also VQ35 combustion chamber are not as compact and efficient as 3.0 c/c's. Tons of room on the periphery for end gas to hang out. That combined with the increased distance for the flame front to travel caused by the increased chamber volume and bore diameter = a tendency to knock. There's a reason you don't hear of this nearly as often with 3.0's.


I'd run a catch can (the installation and use of which has been discussed ad nauseam throughout the VQ world.) If one isn't performance-oriented, reducing the base timing doesn't seem like such a bad idea either.

if you decide to do the 1/3 1/3 1/3 thing make sure you put it in the vacuum hose very slowly while reving the engine gently. You dont want to bend anything.

I read somewhere Nissan is known for ignition coil issues and that spark knock(pinging) is the cause. I'm really trying to get to the root of this problem. I haven't tried any treatments yet, but I'm not sure that would work, I only used 93 since I got the car (15k mi ago) and the pinging is not any better. This is my 2nd maxima that does this (1997 was the 1st one). I am not completely sure its the engine design flow for the VQ since I've known 2.5 altimas that do the same (and they can use 87 octane). Drives me nuts!!!

I would like to read that tread "sound comes from the way the injectors fire under light throttle" Thanks

Knock is an effect, not a cause.


QR25's are based on the VQ35 architecture. This was published by Nissan engineers but what do they know..

I would think if u have engine knock then u wd have decresed performance. And im surprised none of u guys has mentioned a knock senosor as the problem. They do not trip the CEL and would kinda get better with high octane fuel but still need to be replaced. Check to see if the knock sensor is working

A inoperative knock sensor results in retarded timing; a "safe mode" so to speak.

the pinging on my car has completely gone with 8 bottles of fuel system cleaner on each fill up and one can of seafoam in the gas tank. I would be using the fuel system cleaner on every each oil change just to keep the injectors clean and avoid the future pinging sound.

Audible knock is gone. Drill a hole in your firewall and you'll hear some. :laugh: