Weird Sound

[p3aker]

Hi Guys,

a few weeks ago, I change my transmission oil and filled it up with PENTOSIN FFL-2.

Now every time i start my car, about three seconds after ignition there's a fairly loud creaking sound coming from under the car (it sounds like something's moving/engaging, not sure exactly where its coming from.. sometimes its at the back, sometimes it sounds like the middle and sometimes it sounds like its coming from the transmission)

but there's no problem with gear shifts.. so I'm a little scared!