2003 G35 Sedan transmission Problem in reverse

[sullymon]

Well...less than 24 hours after purchasing my 03 G35 sedan, I've discovered a transmission problem. My car has 81K miles on it. When I shift into reverse and then begin backing, under a fair amount of acceleration I get a heavy metal "rattle" which sounds like it's right below the right side rear passenger floorboard. I haven't noticed any sort of problems in any forward gears. If I back slowly with little acceleration, I don't hear anything at all but under load of any kind, I hear the rattling. It's similar to what kind of sound you would hear if a large piece of metal were spinning around and hitting the floorboard. Am I looking at a new transmission for Christmas?

[elwesso]

DO you feel any vibration?? If it sounds like it coming from the seat it could be some other things...

Do this: Press on the brake as hard as possible (and put the parking brake on for good safety), and then press the gas all the way down in reverse. Do this for just a few seconds and see if the sound happens again... I want to see if its only during movement... Do not, under any circumstance do this test for more than 10 seconds. If you need to do it again, let off and let the vehicle rest for a second and then try it again... You wont hurt anything but its not recommended do this test for more than 10 seconds.

Welcome to NICO!!!

[sullymon]

I did the "brake/reverse" test. It did not make the sound when doing that. When I did a normal reverse under load today, I listened a little more closely and it seems like the sound is coming from an area more localized to being beneath the console. Any ideas? I was supposed to drive this car to Evansville, IN tomorrow but now I'm afraid to hit the road for any length of time.

[elwesso]

If its not doing it when the car isnt moving, im inclined to think its not related to the transmission...

I think its probably just a loose heat shield, theres a bit of exhaust related things right in that area.... Its weird because sometimes it will only do it in reverse, I had it happen on my Q where it would only do it with the foot on the brake in reverse.

bottom line is I dont think its really an issue, and I wouldnt think too much about driving the car.

[sullymon]

Thanks. I'm going to call the dealer tomorrow and see if they can have a quick look at it. I'll reply back when I find out what's causing it.

[sullymon]

Problem solved. I took it to the dealer today and found out that it was a loose driveshaft mount. They tightened it and sent me on my way with no charge!