190e engines will have timing chain problems , they are very rattleing and loose engines to begin with. As for 300e like I have said before ( timing chains in these cars rarely go bad ) Yes they stretch a little but nothing like the famous v8 engines. I know I will get over half million miles out of my 103 motor cause its probably the strongest and most reliable gas motor built by mercedes except for the 104 and 119 they are excellent also.

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euro 287
Mercedes Technician 7 Years (retired to Hyundai)
2000 Dodge Durango
98 Mazda truck

At close examination of my failed chain, it appears that the holes for the pins did elongate until there was not enough material left to hold the pin in place and it pulled through.

I not only replaced the timing chain, but replaced the rail, guide, oil pump, oil pump chain, and cam sprocket. (Not including head parts)

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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)