We recently got a wrecked 2005 S4 that we parted out. We started and ran the engine (normal chain noise at initial start) and it ran smooth. We ran it for about 10-15 minutes then did a compression test that turned out good (175-180 through all cylinders).

So a couple weeks later we get an order for the engine from another auto recycler that then sells it to an auto repair shop. A week later the auto repair place calls and says the compression is about 90 lbs in each cylinder.

Any ideas?