Oil pressure gauge weirdness

[Joe Larussa]

Thoughts on fluctuations in oil pressure reading? Time to overhaul gauge or?

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[DonMuncy]

If it were me, I would check and see if it does it on the ground. If so, plumb in another gauge and see if it does the same. 

[Joe Larussa]

Doesn't really do it on the ground of course.

[KSMooniac]

It could be the ground wire...try tightening the screws around the strip gauges. One of them holds a ground wire to the back of the panel.

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[Joe Larussa]

12 minutes ago, KSMooniac said:

It could be the ground wire...try tightening the screws around the strip gauges. One of them holds a ground wire to the back of the panel.

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Good idea!

[KSMooniac]

Good idea!

You might need a wrench on the back side...so you might need to pop the glareshield out for access. Might be worth disconnecting the ground lug and scotch-brite the back of the panel and the lug.

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[flyboy0681]

Mine did the identical thing, except it swung  ever so slightly more to the left, into the top of the yellow.  At first I figured it was a grounding problem since we had issues only a few months before and it was the same symptoms. When I landed I checked the oil, only to find none. The tear down and ensuing overhaul were not a pleasant nor cheap experience.

I would have thought that the needle would have been pegged to the left, but this is what we can expect with 35+ year old machines.

 

[Joe Larussa]

On 2/14/2018 at 5:17 PM, flyboy0681 said:

Mine did the identical thing, except it swung  ever so slightly more to the left, into the top of the yellow.  At first I figured it was a grounding problem since we had issues only a few months before and it was the same symptoms. When I landed I checked the oil, only to find none. The tear down and ensuing overhaul were not a pleasant nor cheap experience.

I would have thought that the needle would have been pegged to the left, but this is what we can expect with 35+ year old machines.

 

Uh? Where did the oil go?

[flyboy0681]

3 minutes ago, Joe Larussa said:

Uh? Where did the oil go?

Teardown found a stuck exhaust value so it all burned up. There was absolutely no indication on the panel that something was amiss, oil temperature was in the normal range and she was running very smoothly even until shutdown.

[Joe Larussa]

1 hour ago, flyboy0681 said:

Teardown found a stuck exhaust value so it all burned up. There was absolutely no indication on the panel that something was amiss, oil temperature was in the normal range and she was running very smoothly even until shutdown.

How many hours did you have on the engine?

[Joe Larussa]

On 2/13/2018 at 8:10 PM, KSMooniac said:

It could be the ground wire...try tightening the screws around the strip gauges. One of them holds a ground wire to the back of the panel.

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Just came to mind, I have the old style gauge where a hose hooks up to the

gauge.

[KSMooniac]

Still worth a try as the gauge has to translate the oil pressure into a needle movement. I believe that is an electrical operation.

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[flyboy0681]

34 minutes ago, Joe Larussa said:

How many hours did you have on the engine?

1250

[Joe Larussa]

4 hours ago, flyboy0681 said:

1250

Ouch

[Guest]

A Bourdon tube pressure gauge is purely mechanical, no electrics required other than if it has an internal light bulb.

Clarence

[Joe Larussa]

Flew three hours today. Gauge couldn't be more steady! I give up.

[Guest]

You might remove and check the oil pressure relief valve.  Lycoming S/I 1172C may apply.

Clarence