Low oil pressure ---Continental O-470

[Piperpiper]

Hello friends,

  Nice to be with the group of airplane lovers.I have a friend who maintains a Cessna 180.Its Continental O-470 experiences a low oil pressure level.it only registers 25 psi at 1700 rpm and goes to zero when the engine is idling.We have tried six units of different type oil pressure gauges.all registered the same 25 psi at high rpm.we tied detaching the oil pressure line going to the gauge,the oil spurted intermetently in small spits instead of a solid line of oil discharge.we have tried adding and taking washers from the oil relief valve but the oil pressure stayed the same.
 We haven't tried tinkering with the oil by-pass valve.Could anybody please help us with this problem.No metal sediments were found in the engine oil when we drained it.Has any body experienced the same problem with this particular engine?please,let us hear from you buddies.
 Have a pleasant New Year to all!!!!

Godbless,
Jess

[jaysmiths]

I know this thread is a bit stale by now but here's a response just in case you are still looking; I have an 0-470 recently rebuilt (by me) and if the issue is not the gauge I'd suspect engine bearings being worn or oil pump gears/housing with wear. Either of these things will cause low pressure and are often typical of high-time engines.

[jaysmiths]

One other thing---the 0-470's came with either a fixed pressure relief valve or an adjustable one. If it has the adjustable one, it's worth a try to back it off some.