oil pressure 75 TwinSpark?

[Lars Arvidsson <arvid@xxxxxxx>]

Hello friends out there!
I'm a little worried over the oil pressure readings in my 75 twinspark
'90, 160000 km
When the engine is cool, I get abt. 3.5 bar (51 psi) at 2000 rpms.
As the engine heats up, the oil pressure decreases, of course, and gets
more
direct associated to the rev. But, a few minutes after 80 deg C is
reached, the pressure suddenly drops
to abt 1 bar (14.5 psi) at even as high rpms as 3000. At idle the needle
doesn't even get of it's rest...
The oil I use is Castrol RS 10W-60.  What I find unusual is the sudden
drop of pressure.
I guess there are some pressure regulation stuff inside the oil pump
(springs and balls?)
Can they cause this behavior? Or can a oil pressure sensor be this
tricky?
Or a worn-out oil pump...
All suggestions are welcome.

Lars Arvidsson, Kumla, Sweden   CAR-member 11190

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