maximaman1997

My 97 SE has a little problem and I want to know if anyone else is having the same problems. Under slow acceleration from say, a speed bump or in the parking garage around corners, I have noticed a slight knocking. If I give it heavy acceleration, no issue. I just had the 60K service done that cleaned throttle body, injectors, replaced fuel filter and spark plugs. I run the KN air filter element right now and have tried every two tanks or so to try different gas stations and grades of gas. I also use full syn Oil for the last four oil changes.

When I was getting the service done, the mechanic at Mossy Nissan here in Houston, TX said that noise is pretty common on our engines. I consider that noise to be an issue myself and want to get it stopped before modifications. Anyone else having same issue?????

got rice?

iTrader: (2)

Engines are more likely to detonate under full load, low engine rpms, and hot weather. This is because the vast majority of the torque is produced from 1800-3000 rpm.

What octane are you using?

What heat range plug is installed currenty?

What is the timing set at?

These are usually the three main culprits for detonation (low octane, not cold enough plug, advanced timing).

Whitemax

I was suffering from knocking as well. I thought it was the gas or something, and I had my mechanic ( a Nissan god) look at it. He asked if I was running Full Synthetic ( I was) and he told me to change it. To run either 20-W30 or the oil used for high mileage cars. said that the knock was atcually a rattle in the timing chain, because there is a tentioner that because the synth oil is a bit thinner, it can't build up enough pressure to keep the chain tighter. I thought he was making it up, but I listened to him, and the knock is now gone. How many miles do you have on your car?

maximaman1997

Just under 61K miles. Answer to other questions, I live in Houston Tx where it is in 90s ambient air temp now and the Octane of gas was the highest at teh pump but when the knocks weren't going away, I went back to the middle which is 89 octane I believe. The plugs are just installed Platinum plugs from Nissan dealer. I just had the 60K maint done. THe knocking/pinging was present prior to tune up and is noticeably better after the tune up with all the stuff cleaned up and normal stuff replaced.

I'll go back to a standard oil.

My biggest fear is that some of this might get louder once I start the modifications.
I am thinking that the underdrive pulley from Courtesy Nissan will be first to swap then either the Apexi or greddy catback exhausts. Brighter side, the exhaust may be load enough that the slight engine rattle won't even be heard. (LOL)

The_quorum

on regular 87 pump octane gas since the company mandated it a couple months ago (they foot my gas bill, so I don't have much say in the matter)...I didn't notice any knocking/pinging except when I went up an 18% grade in "D" at 35-40mph and it tried to stay in 4th gear (dumb transmission)...I'd look into some other possibilities other than the gas first. Oh, I've got 92k miles on my car now.

max808

I thought you weren't to switch back to conventional oil once you start using synthetic? Or is this a myth? Something to do with the engine can't compensate for the incresed friction of conventional oil.

erty67

iTrader: (104)

I hear the same thing in my Maxima. I've brought it to two different Nissan Dealers and the mechanic's at both say it is normal in these engines. They feel there is nothing wrong with the motor making that noise. I feel they need to go work for FORD or something!

Whitemax

I asked my mechanic about switching back, and he said that ws just a myth. I've always trusted him, and he's never steered me wrong. And it did fix the problem. He also said that that noise is common with our engines. Anyway, switching over once to see if it corrects the problem couldn't hurt.

deezo

iTrader: (3)

I noticed knocking and pinging when I used 89 octane fuel. When I upgraded to 93, the noises were gone. Give it a try.

maximasrule

ok here is the deal.. there is nothing wrong with the noise IF it is the chain... its not goin to break and ruin your ingane. although if it is predetination it does matter cause over time you can blow a whole in your piston then your screwed. there is nothing wrong with changing back from sythetic. BUT NEVER MIX THEM because it will gumb up you engine overheat and youll blow a gasket or worse sieze a pistion. i run high grade gas, 10w-30 castrol gtx, and clean my car 3 times a week...uh i dont think the cleaning matters but hey i have no noise problem and i get compliments on my car so hey be your own judge

dan

vmok

a little pinging during acceleration is ok... constant is not.

car's today run so efficient by being allowing a certain amount of ping. the ecu will start leaning out the fuel mixture and advancing the timing till it senses ping through the knock sensor, at which point it will either provide more fuel and/or retard timing, etc...

this allows the car to run at max efficiency. i noticed that my 97 5sp pings slightly, and so did my 96 auto. it happened only during light roll on acceleration or when the grade starting going up.

using 87/89 octane fuel shouldn't hurt the car. but it will not allow the car to run at it's peak efficiency. the $ you save because of the lower $/gallon will make the gas mpg go down because the car can't advance timing/lean out the mixture as much.

-V

got rice?

iTrader: (2)

Like I mentioned earlier, detonation is more likely to occur when the engine is at lower rpms, top gear, full load.

As far as detonation being "normal".. uh.. no. It is not something you want your car to be constantly doing. You'd be a little ****ed if it kept on detonating and created a hole in your cylinder wall and/or piston. Can you say 'rebuild'?

vmok

I agree with you on constant ping/knock/detonation. But I think it is normal to hear a slight amount of pinging if you've been cruising constant rate a while and have just squeezed the accelerator. The pinging should go away momentarily. I read somewhere that for cars to run at maximium efficiency, a slight amount of ping/detonation/knock is just part of the ecu adjustable for conditions. i.e. after constant cruise where the ecu has advanced the timing/leaned up the fuel for maximum efficiency, squeezing on the accelerator might cause a slight lean condition as the gives more fuel, checks the results, and if knock continues, retards timing.

-V

got rice?

iTrader: (2)

In all my years of driving/racing (on the street and at the track) not one of my cars have ever detonated. The only thing to detonate is my lawn mower, which pings if it's really hot out and I put in old gas LOL.

Optimal power on a fuel injected vehicle is made when the air / fuel ratio is approximately 12.8 to 13.1:1. Detonation is going to occur when the mixture is leaned (beyond 14.7:1). You are not going to make optimal power beyond the stochiometric point.

vmok

Well, you're definitely the expert here. But I think in the owners manual that it says a slight amount of occasional ping is normal as the ecu is adjusting things. No I don't have the manual with me, but will see if I can find it and post it later...

-V

vmok

Found it... more specifically,
page 9-4 of my 1997 Maxima owner's manual and
page 9-3 of my 1990 Maxima owner's manual

states that...

"However, now and then you may notice light spark knock for a short time while accelerating or driving uphills. This is no cause for concern, because you get the greatest fuel benefit when there is a light spark knock for a short time under heaving engine load."

-V