Replacement Oil Pressure Sensor

[Corefile]

@Dynon
I need to order a replacement oil pressure sensor - is this the correct part number: 150 PSI Kavlico sensor (P/N 103757-000)
for continental 6 cylinder

 

[Rhino]

Yes.

 

[Corefile]

To close this out for anyone else - I heard back from @Dynon - for the Certified installation its

503851-000: [PMA Version]

 

[Rhino]

Kinda weird. A Continental is a Continental, certified or not.

 

[Rhino]

I see what they did. The 503851-000 isn't the only one you can use. It's the only one available through Dynon. It does make you wonder though, why they would list different part numbers in the different installation manuals. A Continental is a certified engine, no matter what aircraft it goes in.

 

[Dynon]

There are different part numbers, sometimes for the same underlying product or sensor, for experimental and certified aircraft. Even though they're the same, only the certified part number is approved, so make sure to buy the right one. In any case, you're after
503851-000 Oil Pressure Sender - Kavlico v2, 1/8-27 NPT, 150 PSI

 

[Rhino]

Things are always soooo simple when the government's involved.

 

[Corefile]

Ordered the new certified one but that did not fix the problem.

Problem - on startup (and only startup, it never happens any other time, and only does it once per start: after about 4-5 minutes after initial engine start - my oil pressure gauge will get a red X through it, but it will clear after 2-3 minutes, and then operates normally for the rest of the flight. This is very consistent, and it only does it the one time shortly after engine start. I was concerned the first time that I my have I lost my oil pump - but it is not the case.

I tried replacing the sensor. But it still has the same behavior.

 

[GalinHdz]

Sounds like a wiring connection issue. A wire to the sensor breaking contact with engine vibrations. Check the crimp and don't ask how I know.

 

[n144sh]

Agree wiring connection, either on the sense line or you could have a poor ground. Make sure your engine is grounded well to airframe. In addition you can terminate one of the EMS harness ground wires to a convenient ground location on engine.

 

[GalinHdz]

Yes, make sure your engine is well grounded to the airframe with a ground strap. The Dynon EMS must also have a good ground connection.

But you need to connect the Kavlico oil sensor ground wire to one of the Dynon EMS ground pins, not to the engine or airframe. This way you avoid ground loops between the sensor and the EMS which can cause bad signal indications by the EMS module. Ground loops are a common issue with low level voltage signals like those read by the Dynon EMS.

 

[Corefile]

The Kavlico oil sensor is ground to the Dynon EMS ground. So before I cut open all my wiring bundle harness shielding, and the shrink wrap - I want to try and understand the logic (i'm no electrical guru) - but check youre wiring sounds like a knee jerk answer - kind of like "did you reboot your computer". I will explain why I believe, and as I said - I'm no electric guru so maybe my logic is off. But here it goes:

1) loose wire/connection - I have a hard time with this being the problem - If it was a loose wire I would not expect it to be consistently (every single time) about 2 minutes after startup - then have the red X for about 2 minutes, and then go away. And it never happens again till the next time I startup, then the same thing, about 2 minutes in, red X for about 2 minutes then it goes away. I don't see how a loose wire/connection could cause that same scenario consistently - I would think there would be some inconsistency in the behavior - not clock work like precision.

2) Bad Ground - hmm I don't now maybe? But if it was a bad ground - why the exact behavior? is there a way to test the ground from the sender side, with an amp meter or something?

 

[Rhino]

1) I will in no way guarantee it's a bad connection, but bad connections are often temperature dependent. The metal expands and contracts with temperature, and a bad connection might only be prevalent within a certain temperature range, such as what you might see four to five minutes after engine start. Again, it may not be the problem, but there is a reason why it might only occur at certain times. And please remember, although no one else is guaranteeing a wiring issue, they've seen wiring problems cause such symptoms many times before. That's why they're recommending it as a likely cause.

2) Not sure how you'd be able to do that with the engine running for several minutes. But since I have no personal experience in that regard, maybe someone else has a good idea.