I had the timing chain rails break on my 92 500SEL which shares the same engine. I was told that they were made of plastic and that they had broken into small pieces which fell to the bottom of the engine into the oil pan. I noticed that the oil pressure was not acting right when it fluctuated between 0 and 3 during acceleration. It was lucky that I did because the broken pieces of plastic in the oil pan were being sucked up against the screen of the oil pump which restricted the flow of the oil to the engine. If I would not have noticed the problem, I could have done more damage to the engine by depriving it of oil. When I it fixed I told them to replace all that was broken or possibly braking in the near future (car had 90K), this is the listing:

1 119 050 02 16 SLIDING RAIL, LEFT $9.08
1 119 050 03 16 SLIDING RAIL, RIGHT UP $10.45
2 119 052 11 16 TIMING CHAIN GUIDE$11.56
1 119 052 09 16 SLIDE RAIL, TOP GUIDE $5.78
1 119 050 04 16 TENSIONER, RAIL $44.00
1 119 094 26 82 HOSE, CRANKCASE $110.00
1 119 050 17 11 TENSIONER $155.10
1 002 997 84 94 CHAIN, 119.>216 LINKS $283.80
2 119 158 01 02 DISTRIBUTOR CAP M119 $235.40
2 119 158 03 31 ROTOR M119 $107.80
1 119 180 00 09 OIL FILTER M119 $11.55
1 119 010 14 30 V/C GASKET KIT RIGHT $33.55
1 119 010 13 30 V/C GASKET KIT LEFT $33.55
1 119 016 05 80 GASKET $7.99
1 119 094 45 82 HOSE, INTAKE $4.51
1 119 014 06 22 LOWER PAN GASKET $50.60
1 119 052 13 16 RAIL $110.00

__________________
Thanks

Fred Berry
fredcberry@peoplepc.com
92 500 SEL