Oil pressure spikes

[BruceEicher]

Originally Posted by dlloyd3

I have had a couple VDO pressure sensors go bad, giving erratic and high indications on my Dynon. Last replacement got an upgrade to a Kavlico sensor, no problems since.

Same here....with the old Van's supplied sensor, same goes for fuel pressure I found.

[RV7A Flyer]

Originally Posted by AlexPeterson

Oil pressure is the one instrument which needs a mechanical backup. What would you have done if the error (assuming it is an indication error) had shown 20psi?

So do mechanical sensors need a backup? They can fail, too. And I'm unaware of any certificated light aircraft (Cessna, Piper, etc.) which have a backup.

And if you have a backup, and it reads differently than the primary, you now have the problem of "taking two clocks to sea". Which one is right?

The answer to your question, of course, is to land and sort it out on the ground.

[Veetail88]

Originally Posted by RV7A Flyer

The answer to your question, of course, is to land and sort it out on the ground.

which is what I'd have done if it showed 20.

[Jab]

Originally Posted by AndyRV7

If I may, what would cause an actual rise in oil pressure during normal operation of an otherwise healthy engine?

A very high oil pressure can be just as dangerous as low oil pressure. I have had two engine failures, admittedly turbines, because there was a blockage in the oil return line. This resulted in a high oil pressure indication but temperature was normal because it was being read downstream of the blockage.

If you have faulty senders, change them. You don't want to do a precautionary landing and damage something, or yourself, because of an indication problem.

[AlexPeterson]

Originally Posted by Veetail88

which is what I'd have done if it showed 20.

If the nearest airport is 50 miles away, would you take the risks involved in landing on a road? How about, in the case of two gauges, if one gauge still showed normal pressure, one showed 20? If one really believed the pressure was dropping towards zero, a precautionary landing on a road would be the proper course of action. However, if one gauge still showed pressure, and all other indications were normal, I'd fly on.

[chipf]

Originally Posted by dlloyd3

I have had a couple VDO pressure sensors go bad, giving erratic and high indications on my Dynon. Last replacement got an upgrade to a Kavlico sensor, no problems since.
What display and sensor do you have?

I had the exact same issue. With the old Dynon sensor, I would occasionally see high oil pressure on takeoff. But in the last few months it starting spiking in flight. Replaced with the new Kavlico (not exactly a drop in replacement), and oil pressure reading is back to normal.

[sprucemoose]

Does the Kavlico output ohms like the VDO or is it a volts or amps output? The 3 wire configuration has me wondering and I cannot find any documentation.

[AlexPeterson]

Originally Posted by sprucemoose

Does the Kavlico output ohms like the VDO or is it a volts or amps output? The 3 wire configuration has me wondering and I cannot find any documentation.

Voltage is applied on 2 lines, and a signal voltage is measured on the 3rd line. I know in the case of the G3X, the signal is 5 volts. Not sure what range it can handle.

[sprucemoose]

Thanks. That makes the most sense given the 3 wires but sans documentation I'm left guessing.

[Jesse]

With the Kavlico sensors and the AFS 4500:
- Black wire gets a local or an EMS ground
- Green wire connects to the wire that used to go to the VDO sensor
- Red wire gets +5VDC from the AFS pin 19 on the 37-pin EMS connector