MC engine rebuild - low oil pressure

[Huw Powell]

> Thanks for your comments... The pressure was measured at idle when cold at
> 30-35 psi (around 2-2.5 bar), then at idle when warm around 10-15 psi,
> however,  when driving (under 4k rpm), the pressure only rises about 10-15
> psi or so when warm or cold throughout the range.
>
> With other engines I've worked on, seems like pressure is normally much
> higher... Plus, since this engine is newly rebuilt, pressure _should_ be
> pretty high since all the tolerances should be rather tight.
>
> I'm still trying to research other things that would cause the problem on
> this engine.... Anyone else seen this or have ideas?

I agree, your pressure should be higher, cold and revving should peg the
gauge pretty much.  Even with 10w30 oil.

Most of the places where your pressure could be leaking or dropping have
been mentioned, I guess, one place it seems wise to take a look at is
the pressure relief spring/valve thing.  Undo the bolt or oil temp
sender on the bottom of the oil pump, there should be a spring on top of
it, with a metal tubular thing with some holes in it above that.  That
is what reacts at the pressure limit and prevent the pump from creating
too much pressure.  Perhaps there is a burr or some dirt or even
misassembly preventing it from allowing the full 5+ bar to develop?

--
Huw Powell

http://www.humanspeakers.com/

http://www.humanthoughts.org/