Low Rotax 912 UL oil pressure

[Bluey]

Hi all;

 

I have noticed a low engine oil pressure at start up that lasts 10 to 15 seconds when the engine is cold started if it has not been flown for a week or more. Once pressure starts to rise, it rises rapidly to normal levels around 5 bar at low oil temps. Also, in flight, it normally hovers at between 2.8 and 3.6 bar during cruise. It seems to spend more time at the higher end than the lower end. However, yesterday it momentarily gave me a low oil pressure warning light for a few seconds during flight before quickly recovering to above 3 bar. So not sure if it was real or not? The low pressure at start up doesn't occur if I fly on consecutive days or even a few days apart. Once the engine is warmed, no low pressure on start is noticed. However I usually start my engine then turn on my instrument panel. There is a 5 to 10 second initiallisation process before the instrument readings are displayed.

 

The engine is in an airborne microlight.

 

Flew today with pressures very stabe for first 90 minutes of flight before slowly reducing to around 2.8 where it stayed mostly stable. It did momentarily dip to 2.5 for a short period before climbing back to about 3. No inflight warnings today.

 

Any comments would be appreciated.

 

Bluey

 

 

[Bluey]

Did your problems include a warning on cold start up? I'm thinking that a lazy sender unit could cause this?

 

 

[facthunter]

Oil connections.

 

Check for air leaks (into) suck side of oil pump. ALL connections from tank. Nev

 

 

[Bluey]

Thanks, I'll do that. I've spoken to Wal and he is pretty sure it is the sender unit on the way out. Hope he is right.

 

Bluey