Originally Posted by
SLOWBOOST
Its called hydraulic lifters. They all do that and it is VERY common in all mitsu's. Im not sure about the 420a but for the 4g there is a cure thanks to the 3g big bore lifters. You can try flushing them out, cleaning them, or a couple other fixes but nothings permanent.
For the 420a 2.4l lifters are an upgrade. That what i installed when i built my motor. I still get some minor noise but nothing to worry about