Ok so last weekend I did the 2nd half of the 90k service (I did water pump, Timing belt, vaulve adjustment, all new belts, tensioner and tensioner spring) and so now I have some problems, When it idles after being at operating temp it has a hard time running, it tries to die sort of but it doesnt idle is at about 650rpms when warmed up, whe I am crusing at 40mph or around if I give it some gas between 2 and 3k RPMs it makes a weird sort of whisteling sound from somwhere near the engine, when the car is stopped or in nutral and you rev it between those RPMs there is no noise. the car seems to have no loss of power and runs fine except for the idle. Does the timing belt just need ot be broken in or somthing?

thanks for your help!