I have a 07 g35 coupe 6mt. Recently, I started noticing a strange vibrating noise (low frequency and pronounced) when accelerating and reach around 3000 rpm. It starts at then and continue till like 4000 I think. My initial reaction was that it felt like something was loose in the cabin. But after making sure nothing is, the noise is still there. I am still not sure if it is coming from the cabin or engine bay.

It only happens when car is moving and not in neutral. And I mostly noticed it when going uphill.

Any ideas? Whats the worst it can be?

And my oil is not low and it is not the infamous engine pinging between 2500-3000 rpm. Could it be because of drive belts going bad? I need to replace them real soon.

And yeah there is no loss of power at any time.

Responses appreciated!

 

Hard to do an 'internet diagnostic' based on your description. It could be anything. It is a metallic sound?

If so, most likely the heat shield from the exhaust.

 

I don't think it is metallic. Its like "took took took". Yeah its pretty hard to tell just from description.

I am just trying to get a feel if it serious (i.e. something wrong with engine) or not? Since I don't hear it while stationary, I am assuming my engine should be all good and it shouldn't be a major thing, right?

 

Go to a mechanic, preferably nissan certified and have him ride in the car with you.
He should have an idea right away.
BTW, got any mods on the car?
What amount of tread is left on the tires?

 

I know this might sound dumb but also check your license plate and make sure it is screwed in all the way. I had that same problem and heard a rattle noise. I seen that my license plate was loose and tighten it up and no noise ever since.

Good luck!

 

Welcome to DRIVER Jng, nice first post! Noises are difficult to find unlike vibrations that can normally be attributed to tires or suspension!
Gary

 

noises

have about 10 different ones in mine

 

The 'took took took' sound could be the compression rod bushings. Those have a history of going bad pretty quick. Infiniti issued a tsb and a revised bushing to replace the original crappy ones.

 

Maybe exhaust vibrates your cabin. At 3k RPM is when the exhaust kicks in.

Mine vibrates all the time with my exhaust.

 

That does not sound good. Sorry for being such an amateur, but what are compression rod bushings? Part of suspension? And my car is out of warranty so will they still honor the TSB? If not, is it expensive to replace? Or is it necessary to replace them immediately? Or can I keep on driving till they completely break down with no catastrophic result?

Thanks for the help!

 

I figured out what compression rod is and the details. The TSB seems to apply to seden (http://trueler.com/wp/wp-content/upl...ITB08-013a.pdf). Is there any other TSB for coupes?

 

Thanks for the replies guys.

Here is what I have done till now:

- License plate good. I don't even have one on front.
- I don't think it is exhaust because the noise just started recently and definitely not metallic.
- As for other noises, oh yeah there are tons of them at any time. But I still get worried when a new one starts.
- Finally, I took the car to a mechanic the other day and he drove the car with me. Guess what, no noise at all! He drove around for 10 mins and nothing. I swear I heard that noise while I was driving over to him. But the good news, I haven't heard it since either. I think it could have been the passenger seat and with me sitting on it put it back in its place or whatever. But I still don't think it sounded like a seat.

I will continue to monitor and listen closely for the noise. Hopefully, it won't come back. If it does, I will update you guys again.

 

Just one clarification I need that might put my mind to ease. There is no such noise when car is in neutral/stationary and the engine is revd to those rpm.

Can I safely assume that since this noise is only coming when driving, it means that it is not related to my motor?

 

Like I said it's probably the compression rod bushings. Since you're out of warranty, it's going to cost you. You can buy the bushing on ebay for about $25 a piece. But Labor is going to cost you.

As far as TSB goes, There are over 90 of them for the coupe. Actually over 400 for the 03-07 combined.

 

Lol at the TSB count. And then people talk about Nissan/Infiniti being reliable.

Can I delay this repair until it gets worse?