I have a 04' Coupe 6mt, and whenever the car sits long enough to get cold and I go to start it up it sounds like it has a rod knock. It lasts for maybe a second and no more noise. I was just wondering if anyone else has had anything similar happen in their coupe?

 

I heard somewhere that it was the ABS turning on or something, but I'm not sure. Mine sedan does the same thing.

 

It's in the Owner's Manual. My G performs an ABS self-test at approximately 10 mph after it has been started.

 

No it's not the ABS test. I actually hear it as well. Immediately upon starting the car, when it is cold. I think it's just the oil has settled and it takes that second or so for the engine to relubricate itself. I especially notice it when the car has been parked all day at the office, and my parking space has a slight incline to it. Notice it in the garage as well, just not as severe. Also, this does not happen with the M, only the G.

 

Yeah, I think that I have the same sound when I start my 03 G. Like you said its when the car sets the longest when I hear it. At the time I was thinking something isn't right, well I still am thinking that. I also get a little rattle with the knock that's just at start up. Going to get it checked out soon.

 

Ya, its definetly not the abs self check, the car is completely stationary and its right upon start up. Anyway if anyone gets any info from the dealer please post. Im sure they will say its normal, apparently every wierd noise on these cars is normal haha.

 

Welcome LexTechGA.
I've heard the noise b4 too and it's like you suspect that the oil has drained off the moving parts and they're basicly dry on restart.
If it's persistent and a real issue, you could buy a preoil system to pump the oil pressure up b4 starting......> expensive and not convenient.

If it were mine, I'd switch to synthetic in the hopes the oil would stick to the moving parts better and give that extra cushion on restarting.
You haven't said if the oil is dirty and in need of changing. I've noticed too that dirty oil is thinner and will contribute to this problem.
If you are in a hotter climate, you might want to try and slightly thicker oil like 10W30 or even 10W40.

G Rider, The momentary rattle you hear is supposedly normal for the VQ as long as it doesn't last more than a second or 2.
It was described as the timing chain rattling on the cover or block on restarting , and again because oil had drained completely off it.

I've had 3 VQ's now, 2 of which made this rattling noise. I've heard of others describe the same noise.

C.

 

I can't believe this came up now, I finally mentioned it to my dealer this weekend, and I thought it was only in my head, and didn't know how to describe it. My Infiniti dealer said they can't reproduce the problem, and as far as they tested it, everything works fine.
I told them it sounds like a "thump", as the engine cranks over after sitting in a cold. I was suspecting something like an oil pump or something, that shoots oil with great force at start up, and it hits the block, I don't know. As some of you guys, I also noticed this happening mostly in a slight incline after work, when the car has been sitting there for the whole day, but I also hear/feel it from time to time in the morning on a flat surface.
I'm glad I'm not alone. Guess it's just a powerfull pump or something. Next time I'm at the dealership I'll try to go with the tech and start one of their '04s sitting on a lot.

 

the noise you are hearing is the cam chain and sprocket. This had been a bigger problem in the past on the VQ but it stills happens once and a while even on the 05's and 06's

It will not do any damage to your engine its just annoying.

 

This has been covered previously, but it's hard to dig up using the search. It's absolutely nothing to worry 'bout.........Nothing more than the slack in the timing chain being picked up by the adjuster in a cold engine (hence the rattle) I've run Mobil1 since the first 1,000 mi. and it, aparrently, has no bearing on the frequency. By the way, I also have Blackstone do an oil analysis (w/TBN) every 4,000 mi. The results are always perfect and I burn NO oil between changes.

 

Thanks for everybody's response. I'm glad im not alone as well. I had noticed this problem with my 97' 240sx, but u just don't care as much when it's a $7000 car. The timing chain is a new thing for me on the service side (I work for Lexus and we just brought the timing chain back on the new GS and IS.)

 

Funny I read this.. Today I heard a knock or clunk a couple times when I was sitting in a parking space idleing.. it did it all day first time i heard it.. If i short shifted it would kind of make a clunking sound and when i would stop and idle, it would clunk or bang or knock once about every 10-20 sec or so... last night was the first night it got into the 30's all year in florida but my car was warmed up and running so i dont think that was it...