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RGaines

Well Known Member
I was flying today and had an oil pressure alarm in the -12. Dynon alarm went off and oil pressure was zero. I was over a local field at 2,000 and did a precautionary landing at idle. Oil temp did not increase. On the ground there was lots of oil in the sump. I had been aloft for about 30 minutes. I burped the engine and there was the same quantity that I left with. No engine oil in the engine compartment and everything was in place and dry. electrical connections were heat srinked and solid. I started it again and had oil pressure but the engine stopped because I didn't have enough throttle open. Restarted and zero oil pressure and shut down. I got a ride home from a local A&P friend. Nobody around knows anything about rotax engines so the next step is completely unknown. I called van's and the help desk line was busy and went to the operator and then they were closed.

Any long time rotax users have any ideas? It seems to me that when the engine burps that the engine driven pump must be working working. So a sender issue? Very disappointing for a 12 hr old engine.

I will be calling van's in the am but I don't think they have much experience with this engine past the design phase. Raises big questions about sophisticated electronic systems without a wiring diagram.
 
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The obvious

I'd check the wire from the sender where we had to cut the wire off and put ends on it and the wires from the harness. I'd check those first. Would be easy to have a bad crimp or loose connection there would be my first guess.

John Bender
 
I had something similar happen.

I had something similar happen on a trip in a Zodiac 601HD with subaru while crossing western Kansas for CO. Oil pressure kept dropping. . .I kept pulling power and headed for nearest airport. . .just waiting for motor to seize. Little town did have a parts store but not the right sender unit.

I ended up using a $15 mechanical guage they had. It showed good pressure. I taped it under the dash. Flew over the airport until I felt confident it was just a bad guage and continued on. Now if there had really been no oil pressure, different story.
 
I'd say it's a sender issue....

I rent a Remos G-3 (Rotax 912) regularly and there are always problems with false readings with the oil temp, and egt on the Dynon. The FBO is always getting the senders replaced but they don't seem to last very long before they malfunction again. The engine seems to be pretty bullet proof.
 
Don't sweat it. If the integrity of the wiring is good from the sending unit to the dynon then you most likley have a bad sending unit on the motor. This is "common". Not a high failure rate but they do die occasionally. Replaced a lot of them over the years. best way to verify this is to tee in a mechanical test gauge with the sending unit and run the motor on the ground (tie the plane so you can run it at higher rpm). verify the problem is the sending unit and not the motor. I HIGHLY doubt it is the motor. One thing to remember is the oil pump sucks the oil from the tank like sucking thru a straw, a long straw so if you show a oil pressure issue in the engine check here first. One last thing, if you need a new sending unit and it is not covered under warranty you will find that it is a VERY exspensive part from Rotax but we have a solution. The same part from another supplier for a good price. I will post it when I get to the office in the morning.
 
direct drive......

i like a direct mechanical oil pressure guage on my lyc. very dependable. does rotax have one of those? prblem solved.
 
Another way to know if pressure is lost is to use Van's oil pressure switch (IE SPDT PRES-15 SW) and connect a light to it.

With the RV-12 it would probably take a factory authorized mod to do it but it would be a good back up pressure indication. If there is a pressure activated Hobbs meter in the system, the switch is already installed.
 
The Answer

After a long day and the help for many friends we were able to isolate the problem to the sending unit. Hooked up a mechanical guage and it worked fine. Flew it home and took the sender off. Now the problem is going to be getting a new one. The price is $400 and it lasted almost 12 hours. We will see how happy the regional rotax place is about that. Pretty price little part to fail like that.
 
Ouch

and I don't suppose you can pick one up from Dynon and remote mount it on your firewall?

Frank
 
Part # 360-004 VDO Oil Pressure Sender is what we bought for the last batch of replacement units. They are available for around $30-$50 dollars online.
 
Jeromiemead said:
Part # 360-004 VDO Oil Pressure Sender is what we bought for the last batch of replacement units. They are available for around $30-$50 dollars online.
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Jeromiemead said:
The place I got the last batch from, finally found the invoice and the web address. copy and paste and it will take you right to the exact part. http://www.egauges.com/vdo_indS.asp?Sender=150PSI_10Bar&PN=360-004
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Just a heads up...

I think this sensor that Jeromie is refering too would have replaced the (now obsolete) sensor that was being used by Rotax. It was a direct read resistive type sensor. The sensor now supplied on new engines is made by Honeywell and has (I believe) 3 wire connections.
 
Sensor

The sensor is in fact a 3 wire unit and is not a resistive type. My question is why would they substitute a simple resistive $25 part with a complex $400 part that has a potential to fail (12 hrs)?
 
RGaines said:
The sensor is in fact a 3 wire unit and is not a resistive type. My question is why would they substitute a simple resistive $25 part with a complex $400 part that has a potential to fail (12 hrs)?
Click to expand...

I think only the Rotax people in Austria can answer that question with any certainty, but I suspect it is related to making the engine ASTM compliant.

The original resistive sensor is too big in diameter to allow a standard AN style hose to be attached to the oil pump inlet.
I am sorry that you have to deal with this frustration but the reality is that the plain jane resistive sensors are actually quite prone to failure.

Because of your certainty that the sensor is bad I have to assume you have verified the wire continuity from the sensor all the way back to the connector at the D180?
 
Wire check

Yes. The wiring from the end of the sensor wire to the D180 works. We put 2 AA batteries in series and got 12 lbs indicated oil pressure on the D180. Called Van's and was told that was the correct reading we should be seeing. All the wiring and pin connections are correct and solid and worked fine until the sensor failed.

I can understand changing if they did it to reach ASTM standards. The local authorized rotax operation still wants $400 for the part and I can apply for warranty payment. Not much of a warranty.
 
Sensor

Talked again to Van's today. They talked to the supplier of their engines who is not planning on supporting warranty claims. No body seems very interested in making this right. Van's is trying to get some information about who we go to. I also talked to the East Coast and West Coast reps. The people who handle warranty and also parts orders were all out of the office in both places.

I hope that this will eventually get figured out. In the mean time my airplane is down because of it.
 
Vern,
That is my point exactly. I know I am the point person and I expected to be so (kit #2). What I didn't expect was no mechanism for handling issues like this. If electronic stuff is going to fail it fails rather quickly and it did.

After spending $25000 on the engine/prop you would think that somebody at Rotax would just say "we will send you one". I don't think that is going to happen. Rotax doesn't really have any competition so they probably don't feel the need.

The $400 Rotax part is made my Honeywell. I have found the same part but with crimp connections on the top instead of a wire. It cost $79. Think I am going to do that rather than hassle with these people. It does give a peak at Rotax markup pricing.

Sure has put a dent in my RV grin.
 
Could someone post a picture and possibly a rotax part# for the oil pressure sending unit. Even the newest info I have for the 912 shows the single wire unit. I have not purchased a 912 for 13 months and if this part has changed then I will have some problems... thanks
 
RGaines said:
Talked again to Van's today. They talked to the supplier of their engines who is not planning on supporting warranty claims. No body seems very interested in making this right. Van's is trying to get some information about who we go to. I also talked to the East Coast and West Coast reps. The people who handle warranty and also parts orders were all out of the office in both places.

I hope that this will eventually get figured out. In the mean time my airplane is down because of it.
Click to expand...

Richard.

Just a thought......Have you talked to the guys at either Lockwood Aviation and/or Leading Edge Airfoils to help you with the warranty claim??
 
Wow

25k for an overgrown snowmobile engine and FP prop....Makes an O360 with a FP at about the same cost (with longer TBO times AND proper warranty support) seem like a bargain!

In fairness you may not have contacted the right people yet..Remember this engine has been used by lots of people in the past so I assume they can't be that bad.

certainly if this engine came from a Lyclone supplier you'd have one dropped in the mail the same day...I hope these people come up to speed or maybe there is a better engine choice for future customers..

Frank
 
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