Oil pressure needle bouncing-Solved

[SSimpson77]

I’ve checked the historical files and nothing matches my oil pressure  gauge issues I’m  having.

Had the plane for 1.5 years now, over 280hrs since then and a total of 370 tsmoh. Regular oil changes, some at 25 hrs, some at 33 hrs and some at 50hrs. Switched to aero shell 100+ back in April. It does seem to have started since I went to shell oil, but I ran shell oil last summer and no issues . Nothing in filters since owned it.

Oil pressure needle will bounce quickly from 55-80 on start up, then settled down after 25 or so seconds. Run up and flight I have 70-75 psi, but the needle does this fluctuation issue. Once hot, and after a x-country flight, I see 55 at idle but when given rpm, stays up above 70.
Air in line? Gauge going bad (I wouldn’t think so because it calms down after a while)? Pressure regulator ball dirty/bad spring/seat is going bad? 
TIA

PS-I’ve got the JPI900 in a box ready to go, just waiting on slot with mechanic.

 

solved-9/1/2021- on advice from others, removed oil line and found it full of oil. Guess there’s supposed to be air in there to act as cushion. Cleaned out good, retightened, Mechanic checked out my work, ground run…all good! Smooth and stable. I think it all started when my original mechanic taught me to spin the prop by hand when I have the plugs out and doing a spark plug rotation while I’m doing my oil change. It does help prime the oil pump and systems, but the low pressure created can creep oil into the gauge. Thank you all

Edited September 2, 2021 by SSimpson77
Answer the problem

[ArtVandelay]

Could be a bad connection or probe.

[SSimpson77]

34 minutes ago, ArtVandelay said:

Could be a bad connection or probe.

I thought that too, but my system runs an oil line from engine to back of gauge. So it’s a direct connect with bourdon tube. Thanks @ArtVandelay

[markgrue]

Actually it is supposed to have air in the line.   When the oil fills the line you will see fluctuations.   Disconnect both ends and blow the oil out.  Reconnect the line and you should be good. 

 

Mark 

[carusoam]

+1 for following the guide for installing the line… with the air bubble in it…

+1 for following pressure gauges that use a snubber…. Usually fuelP gauges use this device…

Did you see your fuel gauge looking like a windshield wiper too?  These things might be sharing the same lousy ground wire…

+1 buying your mechanic lunch, to discuss the schedule for you JPI install….  

Pp thoughts only, not a mechanic…

Best regards,

-a-

[apriav]

There is a restrictor in the oil pressure fitting on the engine case, was that changed when JPI transducer was installed?

[SSimpson77]

Thank you all for the advice, I will check on that tomorrow. Ceis senders also with the JPI so I can’t wait! I was hoping to do it during some cold IMC time here in Utah, but alas it might come earlier! 
stay safe everyone

steve

[SSimpson77]

1 hour ago, apriav said:

There is a restrictor in the oil pressure fitting on the engine case, was that changed when JPI transducer was installed?

Haven’t done the Jpi yet, still factory gauges

[SSimpson77]

See original post for answer

[Ragsf15e]

22 minutes ago, SSimpson77 said:

See original post for answer

I’ve had same problem but with jpi 930 and the i2s fancy senders.  I spoke with their customer service and they definitely do not want air in the line, but that’s probably different from your older sensor.  Unfortunately the only thing I found to make my system better was to install snubbers in the line.

Id definitely recommend making all your fancy new senders accessible when you install them for the jpi because you might still have issues to address.  @M20Doc has a good example of a firewall mounting bracket that I wish I had.

[Guest]

This one was earlier version.  Doing an EDM 930 in my Comanche soon, I’ll have to see what I come up with for it.

Clarence