I had a 2200 SC auto in for overheating once, and cured a few hoseclip leaks and fitted a new rad cap, then took it for a blast up the motorway (at legal speeds) to test it for about 10 miles, and on a hill on the way back it lost all power and sounded like a tractor with no exhaust, only jusy managing to drag itself back to the workshop. Back there it was still running but with a very noisy bottom chain which I surmised was because the bottom tensioner had exploded/fallen off. I couldn't do anything without turning the engine off, which I knew was going to cause all the valves to hit the pistons, which it did....
It's an ill wind that blows nobody any good though, 'cos I sold the customer a V8 auto I had on the fleet at the time...