I've had the same MCP655 since a64 first came out...been running pretty much 24/7 since then, mathematically MTBF is 50,000 hours or 5 years, it's been 6 going on 7 years lol. I've noticed in the past 6 months the pump has been getting louder, it hums now, turns off and on reliably though. Has a high pitch whine to it now, kinda like an old TV - most people can't hear the tone but me and my wife can and it's irritating, causing headaches. I can turn it down to the number 2 setting and the whine goes away as well as the vibration. You guys think it's time to get a new pump? I haven't maintained the loop in 2 years or so...coolant looks fine, blocks/rads were cleaned well before install. Suggestions/comments?