Mitsubishi Repair: engine noise, piston slap, mitsubishi engines

Question
98 sohc 100900 miles 2.0 liter the engine smokes at start sometimes and when i stomp on it but when i start the engine it will knocks loud at first and then after 10 secs it will go away but you can still hear a little knock but its not loud i was wanting to know what it could be if its piston slap or the vavles od the oil pump or what else it could be and thank you very much

Answer
Jeff,
Check your oil.  If it's low or looks very dirty, you will have noise.  Be sure during your next oil change that you're using the correct weight of oil as recommended by your owners manual.  If the smoke you see is bluish, that indicates some oil is being burned off.  That can be caused by worn valve seals or piston rings.  But if you only get a puff of smoke at the start, it's not a big problem right now.

Piston slap could be a possibility, though that is more common in larger GM engines; V8 gas and diesel engines.  If your valves were hitting, you'd hear a constant and steady pinging noises, that increase the faster you go.  A bad oil pump would cause more of a whining and/or grinding noise.

My guess is that your problem is in your lifters.  Many lifters used in Mitsubishi engines had small oil passages and would not allow oil to pass through very freely until the engine warms up a bit.  It can be annoying and sounds like there is an engine problem.  Fortunately, it's not causing any damage and is not bad for your car.  You could also go as far as having your lifter cleaned if you want to try a quick fix.

Keeping up with oil changes and using the correct weight oil will benefit you the best at this point.  See if you notice this problem a few days after your next oil change.  Hopefully you'll notice the sound recedes.
Good luck!