996 engine from recycler with high leak down
 

I am helping a friend with his 996 which blew the IMS and its engine. He bought a used engine from a breaking yard in SoCal. We did a leak down test on it and one cylinder is at 80% leakdown. I am trying to contact the seller to find the history of the engine.

What is the likelihood of the engine sitting around for a long time having a bad leak down getting better after it has been run in a bit?

Anything is possible... though that's pretty bad. I wouldn't count on it "getting better" especially if you paid a high price for the motor...

Where is the air going? Take off the valve cover, look at the valves... Get a cheap scope and look into the cylinders.

Air is going out the exhaust ...

No way to save this one. Rigged up the engine to do compression test and got zero compression on 6. The engine is going back.

That's the problem with a used 996 engine. Before install I'd scope the bores with #5 and 6 getting special attention, remove the sump/filter and inspect, oil analysis, crank push/pull test, 2000- replace the IMS, etc., etc.
Even then it's still a crap shoot.

It's a shame they didn't check it. There is so much more to these watercooled motors than just the IMS.
Bruce