I seem to have unusually high oil pressure; should I worry?
Editor:
This is cause for some concern. High oil pressure can burst the oil cooler, the filter can, or a marginal field-fabricated hose. The risk depends on
what is causing it. Did you do a recent oil change, with new and
higher-viscosity oil? Did you put in single-grade 50-weight oil, in cold
weather? If so, you may need a regulator valve pressure adjustment. Some valves are externally adjustable, while others require the addition or removal of shim washers (or even a change to a spring having a different pressure range).
The oil pump is a positive displacement pump; its output is directly proportional to RPM, so it has to have a regulator valve. The valve is nothing more than a large ball bearing held on its seat by a spring. If something causes the spring to get gummed up or blocked, so the valve can’t open, it can cause high pressure. When that occurs, pressure will vary by RPM; higher RPM, higher pressure.
If debris blocks the port to the oil gallery containing the regulator, oil pressure will spike badly. Rick Koch lost an oil cooler to this, and is now facing an engine tear-down due to internal contamination. His mechanic suspects it is related to his remote oil filter set-up. You might want to contact Rick and compare notes.
If the regulator is functioning properly, and there are no signs of debris in the oil galleries, something like spun main bearings can cause high oil pressure. But when that occurs they don’t usually last very long; and the PSI drop across the case (front to back), from all internal losses, is only about 10 to 15 PSI; that can’t cause a significant pressure spike. And it doesn’t take much spinning before you have a pretty dramatic drop in oil pressure!
You need to have some in-depth diagnostics done. It is unsafe to fly until you know the reason for the high pressure. If it is related to internal oil gallery contamination, you could have an engine failure due to oil starvation in a critical area, at any time. Hopefully this will prove to have some relatively benign cause, like an oil change or regulator valve malfunction.