O-470 Oil Pressure

[OkieFlyer]

C-182 O-470-R

On the first flight of the day, my oil pressure is always ample and the needle is solid. Often times, after being shut down for awhile and then taking off again, the oil pressure needle will oscillate. It stays in the green, but it will oscillate for the entire flight. Same power settings as before, temps the same as before, everything feels and sounds normal as before. Plenty of oil in the sump.

Any idea what would cause the oscillation?

 

[denverpilot]

How's the system voltage look when the meter is wobbling? It's just a meter and a shunt. Varying voltage will bounce it.

Does the wobbling coincide with the battery returning to a fully charged state?

After that, I'd still see if the actual voltage going to the meter is stable or wobbling before chasing pressure issues.

Nothing high quality about Cessna gauges.

 

[bnt83]

How's the system voltage look when the meter is wobbling? It's just a meter and a shunt. Varying voltage will bounce it.

Does the wobbling coincide with the battery returning to a fully charged state?

After that, I'd still see if the actual voltage going to the meter is stable or wobbling before chasing pressure issues.

Nothing high quality about Cessna gauges.

I have a feeling voltage has nothing at all to do with his oil pressure gauge and its nothing but a bourdon tube type.

 

[denverpilot]

I have a feeling voltage has nothing at all to do with his oil pressure gauge and its nothing but a bourdon tube type.

Ahh I forgot. I thought that one was electric in the 182.

 

[OkieFlyer]

Welllllll, I'm not sure if it's bourdon tube or a transducer. I'll have to go look. It appears to be the original Cessna oil pressure gauge though.

To go ahead and answer the voltage question; the bus voltage reads 13.7, however, voltage is only displayed digitally on the Garmin 696. I'd bet oscillation wouldn't show up on that. The old ammeter stays steady though.

I'll get back to ya.