996 Whining/grinding noise

[hakkiston]

Car is 996 c2

I've got grinding/whining noise coming from my car not sure where it comes:

- The sound intesity follows speed!!

- every gear

- clutch on/off

- gas pedal on/off

I just changed transmission oil and there is nothing. no extra particles, metal or any silver grease from bearings.

Any Ideas?

Edited August 8, 2012 by hakkiston

[Loren]

What (type and brand) new oil to you use for the transmission?

[hakkiston]

Mobilube 1 SHC 75W-90

I have to get the car up and try to listen where its coming from.

Edited August 7, 2012 by hakkiston

[hakkiston]

Correction Sound intensity follows speed, not the rpm.

[DBJoe996]

Suggestion - if the sound follows your road speed, it is suspension, drive gear (CV joints), wheel bearings, or tires, something chassis related, not engine or transmission which would be engine RPM related noise. I would crawl under the car and check all of the above for problems. You could find an open stretch of road, get the car up to speed, put the transmission in neutral and coast to try and identify where the noise is coming from. Helps to have a partner along! Roll down the windows and listen, left front? Left rear? Back or front of car? If you can identify the quadrant of the car where the noise is coming from, it will help you find the source.

[hakkiston]

thanks for support. its gearbox.

[hakkiston]

There's noticable noise in the gearbox when you listen it under the car. Still you have to find the whining when inside the car..

should these gearboxes be all silent?