changed motor mount and now noisy

[bcgreen]

I just installed a new after market motor mount on the passenger side and went to start the engine this morning and found the engine noisy. The drivers side is still the original Mini motor mount. I didn't change the driver's side because it wasn't leaking.
What do you think is the reason the engine is now noisy. I didn't drive it, I just started it and immediately shut it down so I could double check the engine compartment, just in case I left anything in the engine compartment. Everything looked fine.
Any ideas?