Oil pump chain in my 1981 300SD 617.951 engine (267,000 km) failed early
this summer. Failure was most probably due to severely worn pump chain
tensioner (plastic part). High resolution images of the failed parts
can be viewed at http://188.8.131.52/misc/mercedes /.
Q??: How many of the group's readers have seen this failure or have
heard of it?
Because cylinder #1 big end bearing looked ok, garage mechanic replaced
oil pump, pump chain, tensioner, timing chain, guide and tensioner.
After 1,000 km cylinder #1 bearing failed. Conclusion: oil pump failure
most likely causes bearing related failures, necessitating engine overhaul.
Q??: Does the group concur with above conclusion?
Current status: Failed engine sitting in workshop ready for tear down
and detection of further failures this winter. Replaced failed engine
with locally available 617.952 type (from wrecked W123 wagon). Blanked
off hydraulic pump drive. Runs well, good power, no smoke, fuel
consumption is 12.7 km/l (35.9 miles/IMPG = 29.9 miles/USG) in mixed