Noises problem
1994 Other Mitsubishi Models 4 cyl Front Wheel Drive Automatic 161000 miles

hey guys please help
baught the car two weeks ago from a dealership and a few days later a tapping noise occured and got louder.
its only on a cold start i took the car back and they flushed the engine and put new oil in the thing and told me the lifters/tappets had crud over them and they said they cleaned them out the noise is now back two days later.
do you have any suggestions on what the problem would be????

thankyou.