Hans Neureiter wrote:
A while ago a discussion revolved around the 2,000 some rubber parts that
eventual need replacement.
I came across one I never heard mentioned: The hose that lets the waste gate
know when to open.
Goes from the compressor outlet to the aneroid capsule on the waste gate
actuator, kind of hidden under the turbo.
When I changed the motor mounts, I noticed the hose was broken at the
wastegate connection.
Have no idea how long the waste gate was disabled and how important this may
be.
Because the hose was rubber, there was a safety backup. It's called the
overboost sensor on the intake manifold and when it's activated, fuel
enrichment is shut off. This limits the power of the OM617.95 engine to
about 70% of it's rated power so that the engine won't be damaged. It's
important that primary limit be the wastegate as it provide a
smooth/seemless control. When the engine is driven with a serious load
at engine speeds much above 2000 rpm, the wastegate remains open most of
the time, holding boost pressure to just under 1 bar and the engine is
able to deliver it's full rated power. When wastegate remains closed
however, the overboost control operates when boost exceeds 1 bar and
there there is a sudden ~30% drop in power (from ~112 down to 80 hp in
early 617.95 engines or from 120 down to 88 hp in later ones).
Marshall
--
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 182Kmi, '84 190D 2.2 229Kmi, '85 190D 2.0 161Kmi, '87 190D 2.5
turbo 237kmi
