Noise in the back of the car
 

i have an annoying sound coming from the back of the car
it only comes when i put my feet on the pedal and hit the gas

when i remove my feet it stops
it comes when i hit 80 Km/h and up

is it the differential? and whan can i do to eliminate this sound?
i tried the differential sound eliminator oil, nothing happend, still the sound is coming when i hit gas

it's sounds like F1 car naaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaah

anyone knows what to do?

RE: Noise in the back of the car
 

Has the previous owner ever changed the diff? Did you physically check underneath the car for leaks in the exhaust? I would do that, first.

Good luck.

RE: Noise in the back of the car
 

I checked, the exhaust is good, the sound is more like coming from the diff not the exhaust

and the Diff is stock...

i think I'm going to change it coz it might be some of the parts inside the Differential is cracked or something.
my friend has a 3.7 diff, if i want to install it on my car, do i have to change other stuff?
or should i search for a stock diff? and what is the number of it? 3.4?

my car is 1998

RE: Noise in the back of the car
 

Difs are interchangeable. You would have to change the speedo gear in the tranny, to get the speedometer to read correctly, if you change gear ratio in the dif.

RE: Noise in the back of the car
 

thanks for the info

best regards

RE: Noise in the back of the car
 

This is true ONLY if you have an auto tranny. The MN6 does not require any speedo gear change. By the way, the first thing I would do is change the diff fluid and if you use the GM stuff, add the friction modifier as well. This could solve your problem without any other changes.

The stock diff in an MN6 C5 is 3.42:1. Optional diffs are 3.7, 3.9, and 4.1.