kimr42

My 2000 Maxima sounds like it is dieseling at low rpms. I made sure I put in good quality gas and ran some injector cleaner through the tank. I took it to the dealer and they changed the coils in the engine. The engine is still making the same noise. After the engine has ran for a while the noise goes away.

Except for this new problem and $700 lighter in the wallet, I have loved the car.

Any thoughts about what I can do next?

IceY2K1

iTrader: (3)

What brand fuel are you using? If it isn't Chevron, use Chevron for a few tanks and see what happens. What injector cleaner did you use and how many times/miles?

Slight pinging under load, during hot months, and with the A/C on is normal, but annoying.

HitManSE

iTrader: (1)

Really? Ive been told by some mainly by y2kse about the pinging in summer while the A/C is on but I personally have not heard anything. I even have my timing advanced to 17 BTDC I use nothing but premium from either Chevron or Unocal76. Its wierd because here in AZ I was expecting it but still nada. The only thing is does which it didnt be4 is it feels like it pulls timing only in 2nd gear when im at WOT with the a/c. If im at 0mp and just floor it, 1st will fly by no problem, then once second comes in it will pull to about 4500rpm were it feels like there is a lag for a split second then it just pulls to redline. Im thinking its the knock sensor playin around but I never monitored the car so im not sure.

dougb

Could possibly be the ignition coils. Mine had to be replaced for the pinging to go away.

IceY2K1

iTrader: (3)

Your timing advance doesn't make a difference, since the ECU will compensate. Also, I'm not saying it's ALWAYS present, but if it occurs typically under "extreme" conditions, it's not something to worry about.

There are MANY variables that cause detonation and usually the ECU will remove timing to minimize it so it's never noticeable, however sometimes the ECU allows a small amount to be audible yet never enough to cause immediate damage.

kimr42

So should I go back to the dealer, and have them check the ECU, or realize that in the summer months with the A/C on the car will act this way. Or Should I pour in some more fuel treatment and monitor the car.

I though I read that if the knocking gets bad a sensor light will appear, to warn of the danger.

Thanks for your help.

HitManSE

iTrader: (1)

Yea you should, on my car it only gets a slight pull of timing is what is seems, I dont get any pinging that im aware of and this only happend in the summer with the a/c on at wot for a split second so Im not worried, but if your just sitting their ideling and its pinging like you stated. Well you do have two options, stick with premium gas from either chevron for 2-3 tanks and see if it goes away or go to the dealer. Id personally try switching gas first, use only premium. You either pay more now or pay alot more later.

IceY2K1

iTrader: (3)

Yes, since you PAID for new coils. I'd have them MAKE SURE you didn't get a bad coil AFTER you run the tank dry and refill w/Chevron Premium a couple times.

I'm not sure if the MIL will turn on for severe detonation.

bert

I have only had detonation once, and I was asking for it. RPMs dropped to 200-300 and I was pulling off of a stop, actually a slow-down, in second.

If it's pigning at idle there is something WAY wrong.