I definitely heard it on the first start up not so much on the others.

 

mine does this once in a while, i've been ignoring it.

 

is it possible the timing chain was designed to reach proper tension when the engine reaches normal operating temperature?

kinda like how the sr-71 and u2 spy planes would leak fuel on the runway until they got in the air and heated up... then all the fuel cells would seal

 

ya, mine has had a lifter tap before. doesn't happen often, usually when it's below freezing outside.

and yes, the first video sounds like the starter grinding.

about the lifter, there is no real fix to it unless you want to try to find the noisy one and replace it, and even then there is no saying if the new one will lose pressure after sitting either.

Shouldn't hurt anything, it's just slack before it builds pressure.

 

i had a very similar noise during start up but mine was caused by very low oil level according to Infiniti.

 

My vote is for timing chain tensioner.

They can go bad and you will hear lash from the lack of tension. It can cause damage to the crank shaft and such.

If its under warranty still...I'd take it to the dealership to have them take a look at it.

 

Thank you everyone for your input. If anyone else has any ideas feel free to continue to post, but it sure seems like it is either one of the three problems I posted. At least now I have an idea and suggestions to indicate to the techs at the dealership. I'll post updates as the problem gets diagnosed and fixed.

Yeah, its still under warranty (for now, lol) so I'm going to definitely take it in for checkup by the dealership. I have not been driving it in order to keep the mileage under warranty. I also have on my list of things to do before 70k miles to check for oil pooling between the #6 spark plug seal.

I may also, just for the sake of it, remove my oil pan to see if I find anything scary (oil is at 2500mi, so I'm willing to change it now to see).


Don't see why my oil would be low but it can never hurt to check it again.


Its a coin toss because it doesn't seem to be making the grinding noise every single time. When the engine is physically cold (aka early morning) it seems to do it 80% of the time so I guess that's my best bet.

It seems like an even better idea to flatbed it to the dealership in the early morning when they open and have a tech start it right after they roll it off the flatbed. I'm also going to bring my laptop and the videos of the startups for the techs to see (I have 5 startup videos totaling about 10 minutes of footage, I only uploaded the most useful portion to youtube).

I have AAA roadside and i'm going to call them to see how much it would be to tow it to either Infiniti Riverside or Infiniti Tustin. I live right next to Infiniti Metro but those guys are a bunch of *******s and I don't feel like being dicked with right before my warranty runs out.

 

For the record, my vote goes for chain tensioner malfunction. I just remembered now that the last time I changed my oil, the first start up sounded REALLY NASTY with the fresh oil. That would make sense if it was the chain tensioner since more oil than normal would have dripped off of the chain, causing a worse than normal noise.

 

I have the same exact issue and no warranty left

 

im out of warranty too. fml.

 

For the record, I checked my oil levels today and they were perfectly fine, so it isn't a low oil problem.

Sorry guys, the best I can do for you two is report back after it is fixed and share the solution. I'll also make a point of asking how much it would be if it was not under warranty so you guys can get a ballpark for what to expect.

It will probably be another few weeks until I get it into Infiniti since I'm driving a spare car for the time being. It isn't like my G but at least I'm not stranded. I am planning on using this opportunity to do a lot of things I have been meaning to do (brakes, install plenum spacer, grounding kit, camber kit, nismo clear corners, new front tires, CAI, some paint work including full detailing, etc). I am not sure when exactly this repair will take place, but I sure am not driving my G until it's fixed (so I don't risk running out of warranty).

 

I also heard a louf tapping noise at a cold start up many months ago. It has not really happened again. Mine was quite loud and I did not hear it as lound in the video. I turned the car quickly as I heard it. Started tha car again after 10 secs and the noise was still there but then went away in about 20 secs. Has not happened since then.

So a complete mistery for me what happened. Please post if you get any clues to what may be the cause. I am out of warrranty btw.

 

so thats what it is then... ive been wonderng wtf it could be cause thats what my g does when you start driving it and it's been scaring me cause in italy they dont even sell them (g's) so i'm f'd either way... but that clears it up

[QUOTE=MobbinTehG;4511243]No that is not the same issue. The ABS system checks when you start the car and drive past 10mph (or so) for the first time. It tests the ABS system and it creates a grinding noise for about a second or so. You can feel it in the brake pedal if you depress it while it is testing. I know this because I asked the dealership about it after I got my car and a tech explained it to me.

QUOTE]

 

For those of you who can’t hear it in the video, the noise occurs at exactly the 8 second mark and very clear, at the 11 second mark is when the AC compressor kicked in I think. 17 second mark for the 2nd startup. Last startup at 45 mark.

I have been having this clanking noise (lasts about 1 second) upon startup since the second year I bought it, mine is a 05 4dr, I got used to it by now, but would like to see if there is a possible fix.

And you are right, it only happens during a cold start. The rpm usually is around 1700 to 2000 which I guess is normal. However, it doesn’t happen on every cold start, about 2 or 3 times a week for me in the in the winters, doesn’t happen much in the summer of LA, maybe once a week or not even.

At first, I thought it was oil, but then it happened right after an oil change with the correct amount of fluid put back in.

There was this one time where it last about good 2 to 3 seconds and I got freaked out. I went back to the car after 30 minutes in the local market, turned the key and I guess I let go too soon and the engine didn’t start, upon the second time, the engine started but the clanking noise definitely lasted well over 2 seconds at least, wasn’t like the usually morning clank.

I am way over the warranty (100k) and hope this is not something leading to a bigger issue down the line.

Let us know what you find. tia

 

just to add, i also have a noise at a cold start. it sounds like a rattle from the front of the engine. the noise did get louder after an oil change which i did a few days ago. from what i read in the post it could be the chain tensioner. keep us posted on this as i am out of warranty also and would like to know the cost of the fix.