HELP!!
I have a 2006 6mt and I recently started noticing a weird noise that drives me crazy. It only happens for about 0.5-1 second at the beginning of every acceleration and it sounds like shaking an empty beer can with rocks in it. The noise comes and goes and it's not too loud. I barely notice it when I drive to work in the morning but definitely hear it more when the engine is hot. So I think it's temperature dependent. Anyone has experienced this? I drove 140 miles to see a dealer yesterday and they couldn't tell me anything. Any ideas? Thanks in advance.

 

i have the same exact problem and cant figure it out

 

Clutch release bearing. It's normal.

 

lies, i have an auto and this happens to me too. I would like to know

 

Same AT
Something to do with my exhaust system. Just havent had the time to look

 

for op it sounds like the clutch. When you do hear it engage the clutch to see if it goes away to find out for sure.

 

I have the exact same issue, it just started a couple of weeks ago. I have an Automatic 2007 G35 sedan; here's exactly my problem:

Though it fluctuates, whenever I reach approximately 3000 rpm, I hear a rattling or almost knocking-like noise from the dashboard, driver's side. I have heard maybe something is loose? It speeds up as I increase RPM. For the first time since this happened yesterday I got to nearly 5500 RPM with no noise at all, but then it came back again.

Any ideas? It's driving me nuts and I've been driving slowly ever since so I don't stray too far past 3000 RPM. Thanks

 

I'm thinking it could be exhaust too. Maybe a bad 02 sensor

 

I think all these cars do that. Mine has done it for the 8 years I've owned it. It's some sort of resonance in the exhaust system that's RPM dependant.

 

I guess I just need to live with it. It's hard to put up with noise like that in a luxury brand like Infiniti.

 

I'm not sure if I have the same problem. Yours maybe a spark knock. If it's easily reproducible, you should take it to a dealer. My noise can happen at any RPM depending on when I shift. If I upshift at 3k rpm, I would hear the noise when I accelerate from around 2k rpm in the next gear. The noise goes away after about 1 sec and comes back when I upshift again.

 

I'd begin by checking my oil level. If it were an o2 sensor it would be throwing a code and your "Check Engine Soon" warning would appear on your dash. Then I'd want to find out if my timing was correct at the RPMs you described. The bearing you mentioned is called a "Throwout Bearing" and they do dry out but, it would be making a major noise all the time the car is running....everything from a chatter to a squeel. Converters make a noise as do exhaust systems (mufflers) when they broken and lose. You can tell by banging on the exhaust while she's up in the air. (rack)
Gary

 

just some updates on this issue:
I took it to a garage yesterday and the mechanic checked all heat shields underneath the car since they tend to rattle a lot. but everything was fine on my car. Then I talked to him about a second problem(more "play" on the clutch pedal) that I recently noticed and he found a TSB which relates both problems.
Here's the clutch problem: When I pushed the clutch pedal with my hand before, it only went down as much as a click without me exerting too much force. now, it goes down at least an inch. This symptom aligns with the TSB which is on the pivot ball for the clutch fork. It might have partially collapsed or snapped. The TSB also causes a rattle, but I'm not sure if it's the same noise I'm hearing.

 

dunno if I have the same problem but I notice it two times (both have to do with the clutch but also might just be because gas+clutch=vibration as it's a no-load quick revving situation) when I take off I sometimes hear it, and sometimes when I'm pushing the clutch in and hitting the gas to rev match and downgear to engine break or whatever I hear it.

 

I have a 5AT and hear a similar noise in first and second and also when in reverse??
i just took it to a shop today to have it diagnosed... its such a PITA noise to have to live with