912 uls oil pressure

[darrellpralle]

I have a 912 uls with skyview. everything was working fine till recently, when oil pressure at idle started reading 6 psi or less. pressure with engine at 3000 rpm plus is normal. any ideas?

[Dave S]

Hi Darrel,

I also have the ULS but with a different gauge system.......mine goes to 80 PSI cold and drops to 55-60 PSI hot as the oil thins a bit with the engine heat. done that from day one and has never changed. Pressure has never dropped of fthat low on idle.

A couple general issues to check on....

1) Whenever a different than normal gauge reading shows up, it's not a bad idea to hook up a separate gauge of known calibration to see if the existing gauge is telling the truth....for an oil pressure deal - using a standard mechanical pressure gauge hooked up is a good bet.This is a first step so a person doesn't end up replacing parts unnecessarily, or get mislead by a bad gauge reading.

2) Oil pressure that falls off greatly at idle (if that is what is actually happening, barring a bad gauge reading) can be due to a number of causes.....did the pressure drop occur coincidentially with any other maintenance?......if so might be a good idea to check....Engines do have a pressure relief valve with the oil pump... a pressure relief valve sticking open has the effect of an internal leak and will cause the pressure to drop most noticably at idle.

That's not all the possibilities; but it is a couple places a person can start.

Sincerely,

Dave S

[cardinal flier]

A coupple of years ago I chased an erratic low fuel pressure on my Dynon D-180. Tried everything, replumbing, etc., only to discover that the Dynon fuel pressure sender was the problem, even though the sender only had about 85 hours on it. Hook up a manual guage to check the accuracy of the Dynon. Bruce Estes