On Sun, 28 Oct 2007 13:10:50 -0700, hookipa
wrote:

Thanks to all for the suggestions. I pulled the oil cooler and the
oil pressure valves this weekend and all looks good. The Oil cooler
tubes are almost scary clean. I did change the oil, but the only oil
I can get here is a 15w-40 for diesels from BP. Believe it or not,
that or a 20w-50 is all that I can get here. I am getting about 10-15
psi at idle and about 50 psi at max speed. My manual says that I have
seperate senders for the warning light and the gauge. The time the
pressure really dropped off and the light came on was right after
pushing the engine hard for a while (on plane). After I change the
oil and checked the cooler and such, I cruised around for an hour or
so and the pressure never went below 15 psi.

The viscosity numbers mean that when the oil is cold it will flow as
well as 15 weight and when hot won't be any thinner then 50 weight. I
would doubt that is your problem.

You mention that "the pressure dropped off and the light came on"
which implies that both the gage and warning light circuits are
working correctly.

When you say that the oil cooler tubes are "almost scary clean" what
does that mean? The oil side should be full of nasty old engine oil,
it is, isn't it?

You say that you checked the oil pressure valves - plural? If you can
get at the oil pressure relief valve try sticking a washer behind the
spring and see whether that raises either the idle or full throttle
pressure. If it does then either the pump is worn or the spring in the
pressure relief valve is getting weak.


Bruce-in-Bangkok
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