Hello Gentlemen, This may be in the wrong section...but I'm hoping for some good advice. I've been running my TVR1A BB Engine for about a year now & it's suddenly developed a problem When cold it's all loose & spins freely but when it steams up, it will run fine for a couple of minutes & then slowly come to a clacky halt. On trying to turn it, it has become jerky & stiff. I've tried changing boilers & piping to no avail. Can a wise man tell me what has happened? Corrado.