MCP600 Death??

[TbirdX]

Had my MCP600 a while now, a matter of around 4 months anyway, and it has always run at 13.8-14V.
Recently, I upgraded my system and while I was at it decided to move my cooling from the external box to a fully internal set up.
Once it was all plumbed I set about leak testing. 24hrs later, no leaks it's all good.....except I noticed the pump was making a 'cracking' noise. It sounded a little like air but the system was fully bled. I decided to leave it 24hrs to see if it would settle down.
24hrs later I checked on the system. The pump casing was noticably warm to the touch, the cracking noise was still present and while giving the pump a shake, it stopped and then instantly restarted itself.
Since then, it has randomly come to a stop and then instantly restarted itself several times. Also, it now seems to refuse to start up at all at 12v although 14v does indeed get it spinning.

So, I'm not going to trust £1000 worth of new kit to it but has anyone had anything like it before?? I intend to strip it, just in case it's crap in the impellor housing but I doubt it, it sounds more like a dry bearing or something of that ilk.

Any suggestions greatly appreciated