Trader_J

I was wondering if anybody else has seen this with their G37. When I start my car in the morning (especially on a rare cold So. Florida morning), my car make a nasty (valve?) rattle noise for the first 20-30 seconds. I have no idea what it is but it is definitely in the engine area. I tried to blip to throttle from 1k to 2.5k rpm's and it almost stalled while making this noise. It's really pissing me off now. After the car warms a bit, it goes away. I took it to the dealer and they could not duplicate. I'm going to record it when its cold one morning to prove it to them. Please chime in, because I'm at a loss here. The guys in 08' Altima's seen to have the same crap as well (I don't know if it applies b/c our motors are slightly different)...

http://forums.nicoclub.com/zerothrea...postid=3075759

Let me know what you think.
JK

porcupine

I am in Canada, never had this problem

mikead_99

Once in a blue moon I get some pretty nasty valve train noise from my Z when it is cold. Heard some speculation not long ago it could be a timing chain noise instead. It matches your description pretty well. Whatever it is it is disconcerting, but as I've heard it through two winters intermittently with no apparent ill effects I'm not sweating it. If it happens frequently enough for you to record I'd love to hear the dealership's explanation as this really got under my skin for a while.

shumby

iTrader: (3)

live in edmonton canada and no noise so far

Trader_J

Thanks for the replies. I don't think it is a huge issue because it does go away pretty quickly and only happens once out of every five times (esp. when its cold out). I'll just try to record it and see what happens from there...

chilibowl

Only way to prove it to the dealer, is to drop off the car at the stealership and have them start it in the next morning.

S6MT

I've not notice that, but I have notice that my G37 has a very raspy exhaust note for about 20 seconds on a cold start.

My '04 G35 at 40K miles had developed some valve noise that would last about 5 seconds on a cold start.

Good luck proving anything to the dealer. My experience is that they like to pretend like cold start mechanical engine noise is normal. I had a Lincoln Mark VIII that had a cold start piston knock that lasted about 10 seconds. It was loud and embarassing, but I fought with the dealer and the Lincoln regional rep for months and they would never acknowlege it was an issue, even though be both knew they were having piston problems.

Hopefully the Infiniti support will be better than that experience.

UNV-IT46

iTrader: (3)

where in so fl do you live?

csdstudio

My 05 coupe did the same thing, sounded like a blown engine for 3-4 seconds. My wife could hear it inside the house when it happened. 1 of every 5 times or so in cold mornings (below 30 or so).

I could never duplicate for the dealer, probably because I never wanted to leave it overnight, haha. But they acknowledged the noise and said the coupes all make that harsh noise once in a while, valve chain tensioner.

gogetter

iTrader: (1)

Do you run synthetic oil ?? synthetic oil has smaller molecules than regular oil and a lilttle thinner....when in extreme cold conditions SOMTIMES the oil runs out of the lifters and makes that tap sound until some oil gets pumped back up in it. again not always just depends on how much pressure is on the lilfer at engine shutdown. Ive heard of this with other performance cars lilke corvettes....also notice this doesnt happen when regular oil is used.

Trader_J

I live in Davie, near 595. I still haven't seen another G37 down here. Where are you located?

Valve chain tensioner...nice! I'll run that by them when I take it in. Thanks.

One of the dealer techs mentioned not enough oil being on certain parts right at start-up. That would make sense. I still have the original dino oil in the car right now though. I'm only at 1,500 mi.

I'll keep you posted once I get an explanation or try to get this resolved. Thanks again for the feedback.

JK

UNV-IT46

iTrader: (3)

I live in cooper city. the only black g37 i see is one always parked outside a house just north of orange on a side street near bcc central campus...

Ahujadaddy

u sure its not exhaust rattle? Had a similar problem, sounds like what ur describing. Dropped off overnight to infiniti and ended up gettin a whole new muffler!

Noise gone.

Britelite

My problem was the baffles in the exhaust. Sounded like a Honda Civic until it warmed up. They changed out the rear mufler box and it went away.

DetroitG37Joe

iTrader: (2)

OK I am gettin really confused about this whole exhaust issue...When I start my car cold it rumbles louder and is pretty throaty for about 15-20 seconds and then it calms down and becomes normal but are you guys sure this isn't normal? Are people actually getting replaced mufflers out of this and cold starts are getting quieter?

So let me get this straight - with a "perfect" muffler does that mean that after our cars are left in the cold overnight (in currently 15-25 degree Northern weather) and we start her up the next day - the 1st 15 seconds or so should NOT be louder at all? I thought it was natural...! What's the truth on this? Maybe Jason@Riverside could shed some light as to how our stock mufflers are designed and supposed to behave on a cold start.....