View Full Version : Low oil pressure ?
Tango Oscar
3rd Apr 2006, 08:27
Hi all,
I have a 912 Rotax powered Europa, and am starting to get concerned about the oil pressure.
The Rotax manual states the minimum oil pressure is 2 PSI, which is almost exactly what the pressure is. I have checked with another europa owner who also has the 912, and he gets 4 PSI. I have obviously changed the oil a number of times, always ensure the oil is full. At the last 50, I replaced all the oil hoses and cleaned out the oil tank. Still the oil pressure is at 2 Bar.
Anyone any idea what could cause this ?
T.O.:ok:
edited: Because I can't spell.
Hello T.O.
Just a quick one. Have you considered checking the oil pressure sender and gauage. You might very well have a good oil pressure but the gauge may be faulty.
Cheers
snips
I
rustle
3rd Apr 2006, 09:20
The Rotax manual states the minimum oil pressure is 2 PSI, which is almost exactly what the pressure is. I have checked with another europa owner who also has the 912, and he gets 4 PSI. I have obviously changed the oil a number of times, always ensure the oil is full. At the last 50, I replaced all the oil hoses and cleaned out the oil tank. Still the oil pressure is at 2 Bar.
Do you mean BAR or PSI? There's a hell of a difference (like 14.50386 times)
2-4 PSI sounds very low :confused:
Tango Oscar
3rd Apr 2006, 09:49
Snips,
I havn't checked the sender or guage, which perhaps should be the next step. The guage does swing up and down quite violently when at a certain pressure (normally just after starting). This normally only last a couple of minutes, as the oil warms up.
Rustle.
You are correct. I mean 2 BAR, not 2 PSI.:O
T.O.
Paris Dakar
3rd Apr 2006, 09:54
Tango Oscar,
I'm with snips on this one.
Does the pressure reading start off higher than 2 and gently reduces to 2, or is it 2 all of the time? (hope that makes sense).
PD
jabberwok
3rd Apr 2006, 09:58
2 BAR is 29.006 psi.
Tango Oscar
3rd Apr 2006, 10:07
The pressure starts a bit higher maybe as high a 3 BAR, and slowly drops to 2 BAR. I always thought this was to do with the oil becoming thinner as it warmed up...
Paris Dakar
3rd Apr 2006, 10:19
Tango Oscar,
You are right, oil pressure does reduce as the engine warms up - I was just trying to work out whether the gauge is at fault.
I did look at a few Rotax websites, and at least a couple were qouting 1.5 BAR as the minimum operating pressure. Try and get the sender and gauge checked out before potentially reaching for your cheque book.
If the gauge and sender are ok check the relief valve spring I have seen several that are worn on one side. Also check that when the oil's warm the oil pressure dosn't go down when the RPM is raised thats a usual indication that the spring's worn.
I get 45 PSI on my 912S. What Oil are you using? As you probably know the aproved oils have been changed relativly recently. I use Valvoline.
Rod1
Tango Oscar
4th Apr 2006, 10:03
Rod1 - Shell VSX4 is the oil we use. It's what Skydrive recommended
100LL - I think you;re right. I've spoken to a Rotax service agent, and he also thinks it's the pressure relief valve. He's suggested putting a shim in to tighten it !?
Paris Dakar - You're are correct also, the Rotax service agant suggested 1 BAR as a minimum, but other documentation suggests 1.5 BAR. My Rotax manual says 2 BAR though, which is the limit I'll work to.
Thanks all for your help. Really useful info as always:ok:
Paris Dakar
4th Apr 2006, 12:13
Tango Oscar,
I've spoked to a Rotax service agent, and he also thinks it's the pressure relief valve. He's suggested putting a shim in to tighten it !?
I don't want to give you duff info, so if anyone thinks I'm talking bollox please feel free to shout up.
A modification that I used to uprate the performance on my oil pump (car) was to remove the the pressure relief spring and replace it with a 'stiffer' spring. The kit also came supplied with a 'thicker' than normal washer - the end result was a 'high pressure oil pump'.
Perhaps the Rotax dealer is suggesting a similar type 'fix'?
PD
Tango Oscar
4th Apr 2006, 13:03
Yes, it seems a similar idea. The Rotax heavy maintenance manual says there is a shim that should only be fitted if the desired oil pressure is not obtained without it.
Looking at the diagrams, it seems the pressrue relief system is just a ball on top of a spring, with a plug screw. The shim shown looks just like a thick washer, as you suggest, which presumably just acts to compress the spring a little more.
Looks like I may be getting my hands dirty at the weekend :ok:
Tango Oscar the part No. for the spring is 838122 and the shim is 227055. We used to use Castrol GPS but since it's been removed from the list we now use VSX, Its as good as owt.
All AD's Sb's and most of the manuals can be found Here (http://www.rotax-aircraft-engines.com/aircraft/aircraft.nsf/index?Openpage) . PM me if you need any more info
sailing
6th Apr 2006, 06:53
Certainly worth making sure the gauge is accurate before modifying the spring tension though.