1) On cold start the sound is bad, I heard this is normal.
2) When hot the engine is still rought. I opened the hood with the engine running and the sound is rought like an old 4 cylinder. However when the engine run with me inside the car the sound look normal except on neutral if I give some gaz it feel rought again.

By the way I have a Pflow and I often beat this car so I really hope this is a normal thing with this engine. Is their any known problem with this engine?

 

Mine has 100K on it already and it sounds "clattery" in the morning. I did notice my belts are getting old though too. If I rub a bar of soap on the back side of the belt before the first AM start up it is 100 times quieter. I'm due for my first Timing Belt job so I'll do the accesorie belts then too. Speaking of which, anyone done their own timing belt? Normal hand tools, or do you break things and invent new cuss words while swearing you'll "never do it again?"

 

if its like my old 92 pro, i believe you have to pull the engine up to get to the belts because its on the side not the front like old domestics. i was going to do this on my old pro, but had to take it to a shop. i havent looked at my 02 yet, but i think its the same way. so unless you know what youre doing and have the **** to do it with, take it to a professional.

 

Its the secondary manifold butterfly plates chattering. It is normal. Just pull the manifold, remove the plates, seal the holes and do some port matching while you've got it off. This will cure the chatter and give you a little performance boost.