I have a 04 G35 coupe with 78000 miles on it.Recently while driving with windows down, I have realized a rattling sound only when accelerating between 2000-3000 RPMS which then goes away . I bought this car used. However , ever since I bought this car, I have been using plus gas only from SHELL. I had also gotten the engine oil change and used SYNTHETIC OIL.
Can somebody please help me with this as to what is causing this? Is it the transmission is weak or if it sounds like the engine rattling?

Please help

 

Does it sound like it's coming from the front or rear of the car?

 

my car does the same thing too and I found out it was the heat shield

 

It could be either oil consumption issues, clutch chatter, drivetrain, or just a heatshield...

 

+1. mine turned out to be having almost no oil in my block.
good luck.

 

Rattling under acceleration is not a good thing! Start by checking your oil level, then change gas stations to Chevron and use only supreme 92. If you still have the rattling issues stop in at your local Nissan dealership and have them check out the cause. Nissan's less expensive than Infiniti and you might even get better service....I did!
Gary

 

gary were did you get 92 gas? i've been doing it wrong with 91 around LA/Valley area

 

i had a similar issue last week. the sound only happens during acceleration after you take your foot off of the gas pedal during gear exchange. then, there's rattling/almost rasping sound that comes from the front end of the car. i took my 06 MT coupe in at 53000 miles --> diagnosed with bad tranny --> infiniti replaced for free. still... im a little skeptical of what really was causing the problem. where is the heat shield located? does anyone know what couldve caused this? ive always used mobil 1 synthetic...

 

HAHA....OK I didn't know were this guys lives, he could be from the right coast as far as I know. We're about the only state that doesn't have 92 octane, not that it really matters as to how our cars run....
Gary

 

I have the same issue, rattling under the car, sounds like it's near the cat while under load.

Probably the heat shield, def not caused by low oil. I check mine every week. I just haven't had a chance to get it checked out yet.

 

Its definately not the engine oil. I got the engine oil flushed. Before getting the flush done, I asked the mechanic if the engine was low on oil. He confirmed that the engine oil level was not low, however it was dirty. Therefore, I got the engine oil flushed. Even, after the engine oil flush, the rattling sound still exists. Therefore its not the engine oil for sure.
The rattling noise only comes when the car is being driven and that too when the RPM is over 2000. If I press the gas pedal, when the car is in Park, no matter how high the RPM goes, there is no rattling noise.

Could it still be the heat shield?And if it is the drive train how can that be fixed?
Please help as my knowledge on the car engine is very limited.

I also use PLUS gas from Shell? Do I have to try PREMIUM?

Thanks

 

mine sounds like it rattles but thats only under hard acceleration

 

that sounds like the heatshield. i just recently (2 weeks ago) purchased a 2006 g35 coupe, & it is doing the same thing. I used to own a 2007 Nissan and it also did the same thing, so I brought it to Nissan, they replaced the heat shield and it never rattled again at start-up.

 

I have owned my car since new 06 6mt coupe mine has done this since day one. I had a new engine put in about 9 months ago and the new one does it also. (oil consumpution)

I think its spark rattle or valve rattle due to crap gas. If you look in the manuel it says to use 94 octane or some crap that we can't even get. I put in a boost once in a while and that seems to take it away for a couple of tanks of gas. Anyone thought on that?

 

my 05 G35 sports package coupe with 49000 miles dose the same thing.
i thought it might be the gas i fill up with, but its the best i can get in cali,
chevron 91 octane. i hear it in second gear when im next to the center island or
curb on the driver side when accelerating kinda sucks sounds like im burning
cheap gas.