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LIVP Oil Pressure Question (TSIO550E)...Fluctuations Noted
Hello Jeff-
A
few WAGS:
Do the connectors have a wire sleeve and are
they crimped with a ratchet crimper? I had a fluctuating EI fuel pressure gauge
and the shop had used automotive crimpers. I recrimped or replaced the
connectors and the problem went away.
Is the engine new as opposed to reman? I
bought a new replacement engine from TCM and discovered the seat for the
pressure relief was rough. It had to be faced with a hand tool supplied by the
tech rep. If it was a reman I think the odds are against that having gone
unnoticed in previous runs.
I have an aerobatic Continental IO-360
in my Chipmunk. When I bought the plane the oil pressure would be stable when
cold but fluctuate erractically when hot. I did a lot of of
testing looking for a correlation to power settings, tried adjusting
the pressure relief, even changed the spring and plunger; no good. En route
to OSH the pressure dipped to 0 briefly then came back up. Quick landing, fiddle
with the relief, ground run was fine. A while later in cruise it happened again.
Landed, replaced the engine with new. On test flight, the SAME fluctuations!
Refacing the seat didn't help (see above). TCM didn't know what to do. Turns out
it was cavitation- the Christen valve and hoses used for Lycomings (-10) is
too small for the Continental. At cruise settings there just wasn't enough
oil getting to the pump. The engine was originally used for a military
trainer down under- the manufacturer discovered they had to make their own
valve body with -16 fittings. That solved my problem. Do the
fluctuations go away at lower RPM settings? If so there might be
a restriction in the pump supply.
The TSIO-550 Overhaul Manual shows that
the pump body is sealed with silk thread. I know nothing
about it but if there was a pinhole leak in the right
area?
I think the mechanical gauge makes sense as
a check but it's another hole to seal for pressurization. -Bill
Wade
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