Hey all, I just recently purchased a 2006 Red G35 Coupe 6MT .. I purchased the extra warranty of course so I'm fully covered for just about ANYTHING that could break .. well, I've been noticing some noises here and there .. I've been all over the net looking and it seems a lot of other people have small issues with the revup engine that's in my car .. I took it once already to the service department at the dealer with a list of what was wrong and they told me they could no replicate my noises (which is total BS) .. I thought I would list the three major noises here and get some feedback before taking it to another Infiniti dealer .. I'm new to this brand and this engine so I'm clueless as to what's even wrong .. any help is greatly appreciated

1. this noise only occurs when the car is WARM (has been driving for a while) and at low rpm's .. when I hit the gas I get a pinging noise that goes away after I get passed 3-4K rpm .. I did a lot of research any many people believe this is "spark knock" .. I ruled out the bad gas theory because I went to many different stations and used only the best gas at each 93 or higher .. it doesn't effect performance at all but it's soo annoying knowing that people can hear this noise when I accelerate .. it's sort of embarrassing .. some post actually said this is "normal" but I really want this noise gone

2. when starting out in first and second (only if the windows are up) I can hear, at low rpm's, what sounds like a grind .. it's soo strange and goes away when I hit higher rpm's .. I have a feeling this may tie into noise number 3, which may be my biggest problem on the car

3. this is a multi part .. when I'm idle, I hear what sounds like a rattle/grind coming from under the car .. the noise goes away from the clutch is pressed down and then comes back when I lift back off .. also, when I shut the car off without holding the clutch, I hear a rattle type noise come from underneath the car but this noise is never there when I turn the car off while holding in the clutch .. I have a strong feeling there may be something wrong with my throw out bearing or fly wheel or pressure plate .. there's definitely something about this clutch that seems strange .. I read somewhere that it could be my throw out bearing OR flywheel/pressure plate assembly OR transmission input shaft bearing .. I just want these noises gone on a car I paid soo much for ..

if anyone could give me something to go on for each of these so I know what I'm talking about at the dealer I'd be soo thankful .. I'm sure none of these noises are "normal", especially since it's pining and clutch related .. as for the transmission, it shifts well and I have amazing power in every gear so I think the problem lies with the clutch .. the car has 31,000 miles on it and it only had one owner before me so it's less likely that it was beat down hard .. just as a little side note, it sort of feels like the clutch catches a little higher now than when I bought the car about two weeks ago .. soo that baffles me ..

sorry this is soo long .. I just love this car soo much and I want it to be perfect .. thanks for reading and I appreciate ANY responses .. thanks again

 

For your 3rd issue, that is normal for a G/Z equipped with a lightweight flywheel. What you are experiencing is flywheel "chatter". Is it possible you have an aftermarket clutch flywheel assembly on the car? OEM will still have some amount of chatter, but not nearly as much as an aftermarket flywheel b/c the OEM one is dual mass which dampens vibrations and noise. And always hold your clutch in when you turn off the car if you don't want to hear that chatter.

 

I'm really not even sure if there is an aftermarket clutch .. feels stock to me .. I guess because the car is new I'm just hyper sensitive to noises because I want it perfect .. the only time I really hear the noise is when I'm next to a wall, have the windows up when it's dead quiet or when I'm looking soo hard for the noise I block everything else .. it's not "loud", just more of an annoying thing lol .. I guess that's the trade-off with having a fast car :-\ .. more noise lol

thank you for the response .. any help is amazing help

 

anyone else ?? I'm hoping to bring the car in this week sometime .. thanks in advance

 

Even the stock clutch/flywheel assembly can have some chatter (mine did). It's perfectly normal and quite frankly you could spend a considerable amount of money only to have the issue continue.

 

okay everyone .. I have narrowed down that "pinging" noise to one or two possibles .. I know for a fact it's NOT bad gas .. I have been doing research and I'm 90% sure it's "spark knock" .. I found a few sites that describe spark knock and it answers all of my symptoms .. says it occurs when accelerating, driving up a hill or when the engine is under load .. so I guess tomorrow I'm taking it to MY mechanic and saying screw the warranty for this one (even though I've only had the car since the 18th) .. they told me I couldn't go anywhere besides Infiniti or Nissan dealers (which I find the be BS) .. the site also said it could be: the EGR valve not working or a compression ration too high .. I do notice that my car runs a bit lean .. so I might mention that tomorrow as well .. I also read somewhere that someone retarded their timing from 15-13 and it solved this noise .. I'm only posting just in case someone else is going through this .. I will update if the noise is gone .. also, anyone ever have this issue ?? any other possibilities I should mention ?? let me know .. thanks

 

I have the same issue as you do that you found to be "spark knock." I was actually told by the dealership that it was completely normal and related to the intake - which I completely disagree with. I had a tech do a ride along with me and I pinpoint the sound to be between 3700 and 4200 rpms. He agreed that it was an issue. They changed the belts and the ac compressor but could not solve the issue - then deciding that it was normal, they sent me on my way.

Please update if you have found a resolution - I have not. I have discovered the noise and range does increase depending on the intake used.

 

It is my belief that the spark knock is caused by heat.
The air goes into the engine and the temperature is measured at the MAF. Then it goes into the intake where it is heated by the hot intake manifold.
I know some have said that the air is moving to fast to be heated, but it is moving just as fast in an intercooler. And an intercooler can easily drop the temp 50-100 degrees.
So the ecu adjusts timing to correlate with the incoming air temp(cooler than actual) detects knock and pulls timing. But is there a limit to how much timing it will pull?

I say all this because the only time my car knocks is when everything in the engine bay has had good opportunity to soak up heat. Either sitting for a short while after driving or in traffic. A car should run around 195 degrees and mine is usually 200 to 210.

I had a Porsche 944 that had the same issue and Porsche did a TSB to replace the water temperature sensor so the radiator fans would kick on at a lower temperature. This in turn kept the engine running much cooler.

 

Have you checked your thermostat? Maybe it's not opening up all the way to cool the engine properly.

 

If you are asking me, I have a new engine with a new thermostat.

 

Why don't you take a vid of the sound and post it. I'm inclined to think all three are related (for a couple of reasons), but unless I hear it I can't be certain.

 

I actually made a new thread about a rattle noise and it completely turned into a thread focused on THIS ping lol .. but here is the link to the pinging noise that I posted in the other thread


hope you can narrow it down .. thanks

 

I have the same pinging at low RPMs when accelerating. I haven't correlated it to engine temps, but sounds reasonable. I had a scangauge connected for awhile and it normally runs at 190 F. Some days it doesn't ping at all. Could be a EGR problem too since light acceleration is when it's most noticeable - I've had Nissans in the past where the pinhole vacuum line gets clogged with carbon.

 

i have the revup engine that doesn't have egr and it still pings. i am pretty convinced it is from heat. last saturday was nice and cool out (florida) and i didn't have any pinging and the engine was running strong. now today has warmed up and the pinging is back and the engine is weak again.

 

I have been to the dealer 2 times this week for this issue. I just picked it up and was told the issue was resolved. On my way home I hear the same noise. I was told that my K&N air filter and previous owner possibly using bad gas are the reasons.
So they had me purchase an OEM filter(Which I knew was BS to begin with but wanted to give them a chance). I plan on going back on Monday to drop it off again and not pick it up until its resolved.

I have the same sound but believe it to be in the transmission as if its spark knock you should be able to hear it in neutral reving the engine. I can also feel my clutch pedal vibrate when the grinding is taking place.

Side note: Anyone have black spots on their rims and able to get them covered under warranty? I was shafted for that too.