I meant to comment on the compression test results but got lost in the conversation. As mentioned, the compression test only tests the individual cylinders. However, as mentioned earlier, the compression test on the "bad" cylinder could be low, but I have also seen the bad cylinder read too high, because of the presence of coolant in the cylinder. Coolant cannot be compressed and if there is a small amount, it can make a big difference in the compression test results. So look for one that's decidedly "different" but not necessarily low. It could go either way.