Rotax 912 Honeywell Oil Pressure Sender

My CH750 is powered by the Rotax 912S engine. To date I have 90 trouble free hours on the engine with no adjustments required other than tightening a radiator hose clamp. While flying the other day the engine oil pressure started to fluctuate and go full scale both directions on the D180. This really gets your attention! I selected a field for a forced landing, but after flying the approach with Rotax humming along happily (all oil temps & cylinder temps normal) I reasoned I was risking more damage to my CH750 than remaining airborne with a running engine... my home airfield was only 10 minutes away. It was an anxious, but uneventful flight home. I doubt the Rotax 912 would continue running much longer than a minute or two with zero oil pressure. My Rotax 912S has a 2000 hrs TBO, and a new style Honeywell electronic oil pressure sender that replaced the standard Rotax VDO sender used previously.

The Honeywell sender is $400 vs. the VDO sender $45 that Rotax previously used. Bob Robertson of Light Engine Services (Rotax @ Salmon Arm B.C.) sent me a new Aviasport oil pressure guage to wire in as the Honeywell sender (and guage) requires a 12 volt supply to work. By installing this "stand alone" oil pressure guage I was able to prove the Honeywell sender was defective... and not my Dynon D180 as suggested by Rotax. The Honeywell sender is being replaced by Rotax under warranty, and Rotax maintains they have never had a history of failure. In the future if the Honeywell sender fails again (not under warranty) I will replace it with the older VDO sender. It is then a simple change in the Dynon D180 setup menu to select the VDO sender and your back in business. Note :The Rotax 912 in my CH601HD has the older VDO sender..... and 1200 hrs with no trouble.




Views: 1636

Tags: 912, Honeywell, Rotax, oil, pressure


You need to be a member of Zenith Aircraft Builders and Flyers to add comments!

Join Zenith Aircraft Builders and Flyers

Comment by Bob McDonald on June 24, 2011 at 4:46pm
It is a Honeywell that comes on the Rotax 912 series engines after about 2009. I bought my Rotax 912S through Bob Robertson of Light Engine Services 1-250-832-8786. If you want you can order your engines and ask for the older VDO sender...exchanged no-charge. I put the older VDO Rotax sender on, single wire to run and selected VDO in the Dynon D180 menu and it was good to go.
Comment by Rodney Rix on June 24, 2011 at 3:56pm
Bob can you tell me is it a  Honeywell sender that comes standard on the new 912S, or VDO?
Comment by Bob McDonald on April 14, 2011 at 6:48pm
Tach issues are usually electrical connection loose or bad ground. One of the best trouble free, 15 minute install, battery powered tach/hobbs units I have ever used on an aircraft is a Tiny Tach (Aircraft Spruce). Its low also cost to purchase.
Comment by Paul Hammond on April 14, 2011 at 6:25pm

G,Day  Bob thanks for the info i will go down to the local auto parts store today and buy a sender . 

But i also just remember my tacho goes a little sometimes too.Like Dave i have had so many tractor and machinery companys say to me that i was the only that has ever broken on

Comment by Bob McDonald on April 14, 2011 at 7:01am


It is probably not an issue with the Dynon unit. Those oil pressure senders are subject to a high heat and vibration enviroment. Simply replace the oil psi sender first if it a low cost item, then if your problem goes away you have already fixed the problem while trouble shooting the issue. The Dynon is backed by a rock solid warranty...the oil psi senders are "consumables".

Comment by David Gallagher on April 13, 2011 at 9:06pm
Bob, I can't tell you how many times I have had company reps on many different products say "Boy, we have never heard of that failing before" when I know darn well they have. You did a good job of sticking to your guns and presenting independant verification.

Comment by Paul Hammond on April 13, 2011 at 5:54pm

G,Day  Bob

My dynon oil pressure guage goes crazy some times too I thought it must be a dynon thing as I have a jabiru mine seems to only go off the high end of the scale i guess it must be in its tiny electronic brain .let us know how you get on Bob, I better go get vdo guage and sender for backup and peace of mind.

I wonder if any else had similar thing hapen ,let us know

Comment by Heinz Genrich on April 13, 2011 at 9:00am

Thanks,Bob for the great information.That what this site is all about.

Heinz Genrich

New from Zenith:

Follow Up Report:

Weather Maps

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, power distribution panel, Approach Fast Stack harnesses, Dynon and Garmin avionics, and more.

Zenith T-shirts and Hats:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz.

© 2014   Created by Zenith.Aero.

Badges  |  Report an Issue  |  Terms of Service