I've got a random issue with a sound that only happens once a week and only on cold start up. I get this grinding /clicking sound for about a second or two as soon as the car starts. It sounds very similar to when you stick a baseball card in your bike tire spokes. No other issues or codes with the car. Just curious what's causing the sound and if I should be on the lookout for something.

 

Without hearing it, it's probably the typical timing chain rattle a lot of G's have on startup.

If you search for a cause, you'll see a few items such as bad tensioners, or a bad sprocket.

Lot of high mileage Vq's do this on startup.

 

Thanks, I looked up timing chain sounds on YouTube and found a video of the exact sound mine does.


So does the timing chain rattling lead to anything worse? Should I be fixing it ASA?

 

Had you done a Search using "Start up Noises" you would have found what you're hearing is the traction control kicking in! This is a noise you may only hear once every 15 times you start your G. I was concerned the first time I heard it too!
Gary

 

I disagree. The ABS self-check requires the car to move forward to complete. A rattle when the engine is first started is something else.

My car has had the 1 second startup rattle for the last 10K miles (almost to 150K now). It's not the VDC/ABS system. I can hear that noise separately and have been familiar with it since buying the car years ago when it was new. The ABS self-test doesn't occur on my car until I begin to move at around 3-4 MPH. That sound is more of a springing "boing" sound and if you hit the brake pedal at the exact time it does this, you get that ABS engage feeling. I can idle in place for 10 mins and the ABS self-test doesn't occur until the car moves.

This brief startup rattle is something different. Mine sounds exactly like the video above, and lately has been concerning me so I'd like to find an explanation as well and fix it.

 

Thanks Gary, yeah I tried a few searches but couldn't come up with a good phrase to search to pull up anything useful. I ran across this thread which also has a YouTube video of the exact sound. 4 pages and doesn't sound like anybody confirmed the cause but apparently a lot of people have it, so possibly it's normal....

https://g35driver.com/forums/g35-cou...up-engine.html

 

Here's my suspect.

Read Post #7

http://my350z.com/forum/forced-induc...tensioner.html


part of the TSB states that a brief noise is normal and acceptable, but it specifies on the new sprocket. What my question is does this apply to old existing sprockets?

 

Interesting, I guess just keep an eye on it to see if it starts making the sound more often than just random cold start. Idk if it's worth the hassle to open up the timing chain cover to check those out.