01 rough idle/rattle after timing belt replacement

[north1]

Had timing belt and water pump replaced on my daughters 01 camry. Car has 70,000 miles and 4cylinder engine. Was done at local toyota dealership. Noticed that the engine runs a little rough and has a slight rattle at idle, but it clears up when engine rpm is above 2000. Will contact dealer tomorrow but am curious if they could have flubbed up the timing when replacing the belt? Not happy as the car ran like a watch before the work was done. Any and all opinions appreciated. Want something to go on before I contact them.

[socal57chevy]

Does it "hunt" for idle? (rpm surges)
My guess is that it's off a tooth. Even if it is, it should be quiet. Definitely take it back.

[deadrx7conv]

The local dealer here battled with with me concerning the "timing belt kit" vs just changing the timing belt. Whether they flubbed up or not depends on how thorough they were when they did the belt.

[SL Stevens]

Had exact same issue when I changed out belt myself--rough idle until 2K then smoothed out. I removed the top timing belt guard and discovered the belt to be very loose. Apparently, the tension spring on the idler pulley no longer provided proper tension when the belt was changed. I loosened the idler pulley, pulled up and the pulley to tighten the belt, then retightened the idler pulley bolt. Problem was fixed. Next belt change I'll be replacing the tension spring.