2001 Galant Rough Idle, Knocking in Drive.
 

Greetings team!

I've been brought a 2001 Mitsubishi Galant 2.4liter L4cyl SOHC automatic with 103,000mi (to bring back to the road as a favor) that was lent in perfect condition to other family members, but returned a nightmare! Obvious oil control issues (oil EVERYWHERE under the hood), fouled #2 spark plug, bad ignition coils, rough idle, hard starting, all valve cover screws were loose, check engine light (trouble code P0302--cyl#2 misfire condition) and a knocking when placed in "drive" from a stand still, and when the vehicle stops (red light, stop signs). The pick up is slow & stumbles, but smoothes out as speed increases. It used to cut off when stopping or attempting to back up.

So far, i've changed out the fluids (coolant, oil change w/ new filter), spark plugs, ignition coil pack, tightened valve cover screws, ran injector cleaner through a tank of fuel, Computer reset (disconnecting battery), checked PCV valve spring for play and hose for leaking.

The response has been better starting, idle remains rough, knocking continues when placed in drive, but instead of the engine dying when left to sit in drive, it just continues to knock until you accelerate, check engine light was gone, but came back 3 mins after changes. I need to check for vacuum leaks, but I don't have proper equipment (car is at the house..not the shop). I'm thinking the compression needs to be boosted, and it has a LOT of carbon buildup, so I want to hit it with SEA FOAM (1/3 in brake booster, 1/3 in crankcase, 1/3 in fuel tank) to clean it out, get a new valve cover gasket with rings for the spark plugs (to control the oil, and ensure there are no leaks from there), RUN it, and add Engine Restore, and SEAL CONDITIONER after another oil change.

I've owned a 1996 Mitsubishi Galant 5-speed, so this engine set up is different for me..but I want to bring this 2001 Galant back to the streets for them. This sounds like a common problem (the knocking), Mitsubishi fam..what do you think it is? And what do you recommend?