squeak at start-up and idle until about 10mph

[mn box s]

Ok, so when I start my car there is a very loud squeak that seems to go in harmony to the engines speed. At start-up it is about a second and a half intervals but then once engine is spinning at idle about half second. About two to three seconds after car is running the sound becomes more sporatic. The noise seems to get worse as I drive and the car heats up. It really squoks in first gear as I acclerate to about 10 mph and then nothing untill I come to the next stop light and it starts to do it sporatically again. I had the clutch/flywheel replaced I have replaced the exhaust, headers, test pipes, muffler and it was doing this before the exhaust was replaced. I have not checked the pullys yet but not sure if I'll find anything there. Could this be a motor mount issue? Anyone had this problem and what was the solloution, please?