The motor is not trashed. Certain part are though. It is completely rebuildable. I've done two from broken timing chains.

What happened was the timing chain broke. This caused the pistons to come up on the valves that were still open and instead of only bending the valves, the camshaft and cam towers broke. In this case, the cam tower is supposed to break before the cam, thus saving the camshaft. This is not always what happens.

My first timing chain break was at ~230,000 miles and I never found a root cause. The chain may have just failed. It only bent valves and the rebuild, including new oil pump, intake valves, exhaust valves, valve guides, seals, chain guides/rails, cost about $1200 to do.

The second chain break happened at ~200,000 miles I believe. It broke the camshaft into three pieces. I got a used head and rebuilt the engine for about $400. Root cause was a failed vacuum pump.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)