I am going to be the one that complains about a timing chain failure on an M103:

I removed the sump to install a turbo oil return, and found little broken round, what looked like mini head "dowels" in the bottom.

Turns out, they were the outer rollers from the camshaft chain.

Upon close inspection, many more were still on the chain horribly damaged... This is a "Rolon" chain, and I am about to replace both the oil pump and cam drive chains with IWIS brand chains. Mine has the little joining links, so I can just join each of them and rotate them through. Engine is out of the car, mind you!!

I have no idea how many kays the engine has, I purchased it last week second hand.

Luckily I decided to check over stuff, I am also installing an .080in copper head gasket and 12.9 grade head bolts for added security under the duress of boost pressure.

I will surely let you know how that goes!!