Iffy350

Hey guys,

I've had an 07 grand touring for 2.5 years now. She's got about 70k on it with light mods. I daily drive and drift the car. So I took her on some heavy highway runs while on a cars and coffee rally to an event. Had the car driving at pretty high speeds most of the time but nothing new to the vehicle.

The next day I turned the car and a weird humming/buzzing sound that was coming from the engine. I looked up what it could be first thing I saw was to change the oil. Found some thread about some guys saying that once they changed their oil the sound went away, which I was hoping the same for me.

The oil had been in the car for only 25-2700 miles. I changed the oil and filter and the sound still remained. When I rev the motor the sound increase with it.

I searched more and read of NICO that is could be a worn secondary timing chain tensioner. The plastic guides wears down to the tensioner piston. Then the chain rides the piston rather than the guide.


Quote on Nico by SpedDRacing
"Got a buzzing/whinning noise when you start the engine? Does it continue durring driving? While a rattling noise durring crank up is more than likely due to low oil, a buzzing or whinning noise while driving MAY BE CAUSED by worn secondary timing chain tensioners. What happens is the plastic guide on the tensioner wears down to the tensioner piston. The chain then rides this piston instead of the guide, causing a whinning noise. In some cases, a bad alternator clutch (yes, the new alternators have clutches) can cause this. In the situation that your tensioners are to blame, expect to spend from $1000 to $1500 to have them replaced and should include new upper (secondary) timing chains."



Anyone have any other ideas or possible solution? Or could someone confirm that its the guides and that I need to replace the timing chains?

Thanks in advance!

zakmartin

Get a cheap automotive stethoscope with a probe tip to narrow down exactly where the sound is coming from and report back. "A weird humming/buzzing sound that was coming from the engine" doesn't really give us much to work with.

travlee

iTrader: (8)

that windshield sticker reminds me of

Iffy350

apologies for the double post, but the sound is coming from the front cover, for the timing chain on the passenger side of the engine.

I uploaded a video for some sound and view and put the phone close up.

https://www.youtube.com/watch?v=KayY...ature=youtu.be

zakmartin

So in the FSM, referring to EM-53 and EM-54, where exactly are you getting the strongest noise? Again, you're going to need to check this with a tool like an automotive stethoscope or micrphone, and not just with your ear pointed at the engine.

http://www.nicoclub.com/manuals/350Z/coupe/2007/em.pdf

MB037

iTrader: (1)

Was there ever a cause for this noise found out? If you figured out what it was it would be awesome for a resolution post.

Mine has just started to do the same, a little bit quieter than your video though.
Same place, same sound, tied to RPM, etc