When this happened to me a few months ago, I asked my dealer about it. He asked where I had the oil changed last - it was not with the dealer. He said that it had something to do with the oil filter and a check back valve in the Nissan filter. I wanted to call BS on him so I had him change the oil and it hasn't happened since. I will not attest that what he said was true or that the oil change fixed the problem - but something happed!

 

I have been following this post from the beginning, and I still get the initial thump on ignition startup if I have not driven the car for at least a day?. Over the holiday period ther was a 3 day stretch when I did not take the car ou of the garage, then on the 4rth day I started her up and I had TWO thumps or grinds about 1-2 seconds apart?

I get my car serviced at a Nissan dealer, I have had the car 12 months & the oil has been changed at least 6 times-surely it cannot be linked to an inadequate oil change by another party?..

I have been curious & have been constantly checking this thread to hopefully find a suitable explanation for this strange noise, is there anybody out there that can shed any light on this? is it a problem that is related to the Nissan VQ engine and is normal?...is it really something to ne concerned with?...should we take our cars back to the dealer, and try to explain the problem?.....or is that more trouble than its worth?...

any thoughts?.

 

I have heard something like this, and I think it may be the AC compressor. Any of you with the noise have your AC on (or on Auto) when you start the car? If so, or if you are not sure, try it with the ac off.

 

I have the same thing on a 6MT and mine is definately just some valvetrain rattle. If I hold the clutch down for a couple seconds on startup the noise dissappears. Maybe if you guys try holding the pedal down a little longer you can see if its the same issue.

 

the only times i have gotten this was like other people have said, when it was cold out, living in ohio we are now starting to get subzero (cold enough even with my car in the garage), and when i havent driven her in a little bit, usually first thing in the morning. My guess, not knowing much if anything about cars is that this comes from all of the settling of any fluid at night and being a little on the thick side being cold. My hunch, and it has worked so far, was to put the key to the acc. position for a few seconds before turning all the way for ignition. in this position i can hear the electronics kicking in. then i fire her up and since i have done this i have yet to have had the noise again, and we have had some of the coldest weather to date yet. this may be sheer coincidence or i might have stumbled on to something. either way give it a shot. better to be lucky than good anyday of the week.

 

Sounds like the hydraulic tappets pumping up. I used to have a VW GTi that did it every time on start up. A half second clatter. I have to say I haven't heard it on my Z, and sometimes it stands for days on end at the airport.

 

Nope, nope and nope.

The sound you guys are hearing is the same thing the Maxima is plagued with "timing chain rattle".

Currently there is a TSB for this on Maxima (perhaps 350z as well). Most importantly, this will not cause any long term damage from what my Maxima brethren tell me.

The TSB tells the tech to do a cold soak start (let the car sit overnight) and determine which side the "rattle" comes from. This fix is a replacement of the sprocket/gear that drives that side of the timing chain.

I live with it just because I do not trust the Nissan Mech. to tear my engine apart, change it and put it back together.

 

Here is a link to the pdf. They only list Altima and Maxima for some reason:

http://maxima.theowensfamily.com/tsb/NTB03-060.pdf

 

Mine does for a few seconds after the car has been sitting cold fr a couple of days. I also find that wtih the AC on auto when shutting off, it stops ?

 

Hummm - - I've been following this discussion too - - I have the same "noise" after not starting for more than a day - My impression is it's a transmission, throw out bearing, etc?? noise - I've found if before I shut the car off at night, shift into neutral, let out the clutch, idle for a second, shut off the car, then put the car back into gear (first or reverse) - - after a couple of days when I start to car no "scary noise" - - - I'm not sure what we are all hearing - - I guess I'm glad I'm not the only one

 

Had it happen just once to me and having torn down and rebuilt many an engine in my misspent youth, I am convinced that it was the valve train, especially since it was accompanied by roughness for about 3 seconds. I would guess that it resulted from a temporary lack of lubrication. As someone else mentioned, Nissan filters are equipped with an anti drain-back valve. The Fram filters that I use have one as well. However, it doesn't mean that they always work properly in either brand, and this may have caused the problem.

 

My Z has the very small noise the pdf referred to. According to it, its not considered a flaw. For those of you who have several seconds of the rattle, I would copy the pdf and tell my dealer its happening to my Z. I am using Mobile 1, which may help since I'm not driving the car a lot now. After leaving the Z in the garage for a few cold days, I can hear a faint rattle. If it gets worse, the dealer will hear about it.

 

Yes, it's not detrimental unless it occurs for much longer than a second. Mine did it quite a bit this winter (w/ Mobile 1) but only on days colder than 30 degrees. After it warmed up, I have yet to hear it again.

I'm quite weary of letting Nissan service tear down my engine (possibly remove the engine) to fix this problem...so I probably won't take my in unless it is occurring every day at 59K miles.

 

I havn't really heard a noise on startup, but my 04 does make a loud rattling/grinding type noise when I turn the car off.

Anyone hear this on their car ?

 

It's been discussed here too - - - https://my350z.com/forum/showthread.php?threadid=52092o -

Where I posted my $.02 - - -

Hummm - - I've been following this discussion too - - I have the same "noise" after not starting for more than a day - My impression is it's a transmission, throw out bearing, etc?? noise - I've found if before I shut the car off at night, shift into neutral, let out the clutch, idle for a second, shut off the car, then put the car back into gear (first or reverse) - - after a couple of days when I start to car no "scary noise" - - - I'm not sure what we are all hearing - - I guess I'm glad I'm not the only one

 

I drive my car everyday, and it does this every morning when I start it up. The temperature doesn't seem to affect it. There is something in the morning that bothers me more. The first time I apply the brakes I hear a thunk and feel it in the pedal. I will have to take it into the dealer soon.

 

You just linked this thread to itself.

 

Yea I drove my car Saturday night and then I didn't drive it on Sunday except I did start it and pull it out of the garage and then back in for a bit. My 6 speed touring Z is garage kept. I went out this morning and started it up. It was a bit chilly this morning but nothing bad for November in Texas. My windows were all down so I could distinctly hear what I always associated with Valve train noise coming from the engine not the tranny. This knocking/ticking sound was very loud when I started the engine and then tapered off after about 10 seconds. I let the car sit in idle for a bit. Stopped and started it again but didn't hear anything more. I drove it about 20 miles and it seems to be fine now. I was a little over my miles for my next oil change so I went and had that done. Either way that noise was loud enough to scare the sh!* out of me. If I hear it again it goes to the dealer.

 

I have a 2003 Touring with automatic trans, I have heard this noise about 6 months after I bought it. I only have about 13000 miles on it, it stays in the garage most of the time but if I move or drive it, I get that grind/rattle at start-up. I didn’t really think about until now. I will make an appointment with the dealer to check this out further.

 

now i know it doesnt get too cold in texas but this problem is obviously temperature related. i mean just look at this thread. it got much play last winter and when march hit it died down. now that we are entering november and temps are dropping; here comes the thread again.

and oh yeah. my start up noise has come back, been back for the last month or so. thats about how long it has been that cold in the AM here in ohio.

and good luck trying to get a dealer to hear this. only possible way is to let your car sit there over night. come back the next morning and fire her up first thing with the nissan tech there.