Rod Knock! OR is IT?

[Rob1]

My 89 supra was in my garage for a compression test. results were not great, 140,100, 135, 110, 130, 140. So with head in hands i put the coil packs and intake piping and what not back on and fired it up to check a few things.

Here is where it gets interesting, It ran fine for about 1 min, then i headr a knocking noise. Started slow maybe one loud KNOCK every fifteen seconds or so the progressed to a steady, very loud, knocking.

Well i let it idle for about 3 min a week later and it was knocking up a storm. Then like magic is just STOPED! there was still a faint metalic sound but not a knock maybe valve chatter.

So near silence for about ten seconds. then there was one loud KNOCK, after this knock the engine speed fell down to almost stalling, and when the idle came back up the steady knock had returned.

I have repeted this proccess twice now and it follows nearly the same pattern each time.

Any ideas about what it could be? cuz rods dont normaly just stop knocking. any advice would be greatly appreciated thanks