attn techs, need help before I dig into the motor
 

Had somone bring me there 86 that they just got off of e-bay. The car would not start, and replacing the dme relay got it going. At idle, now that the lifters are pumped up, is pretty quite. Give it a little throttle, loud rattle. At idle the motor will have no noise, then it will get a metallic tick from the top and it will idle down. When the metallic tick from the top goes away about 4 secs later, it will get a muffled, but slight, knock from down lower.
When the drain plug was pulled, it was pretty clean with just a few "dust" size pieces.
If a lifter had gone bad, is it possible, that you can get some vavle-piston contact. If a valve spring set has gone bad, same question.
Worst case, con-rod bearings need replacing.
Oil pressure is good though. When the car starts, 4 bar. After the car reaches temp, only drops to 3 bar at idle.
Good compression on all 4, 160
But here is another thing, white smoke out the tail pipe......

Sounds like a bad lifter coupled with a bad headgasket.

AFJuvat

I would also check the rod bearings. As AFJuvat said the white smoke is a bad head gasket. If your gonna pull the head I would get a valve job done and check all the lifters

Yah, sounds like rod-bearings...