Oil Pressure Sensor

[SoaringVA]

I need to order a new oil pressure sensor (mine is acting up).  Has anyone had to source this?  I called Lockwood but they said they didn't have the original part number so I need to get it from Aeromot.

[Thermalseeker]

If it's relatively new vintage, say 2000 and newer, it's probably a VDO. Before you replace the sender try cleaning the contacts at the sender. Also, pull the sender wires off the gauge, then reinstall. Doesn't take much corrosion for them to give false readings. Probably a good idea to buzz the wires with a continuity meter for grins, too. Wires on crimp fittings can fail right where it is pressed. An intermittent connection would give funky readings. If that doesn't work, Aircraft Spruce will have what you need. Surprising Lockwood wasn't any help. Musta got a newbie. They've worked on a lot of X's. I guarantee any of their mechanics would know the part number of an OP sender off the top of their head. 

[HiFlite]

I'm sorry I didn't see this earlier; I have a good VDO sender lying around you can have. My story w.r.t. the oil pressure sender:

I’m told that Aeromot had different setups depending on year of manufacture, so I can speak only to my particular 2005 example. The OP sender dates from VW bugs and its use probably relates to the Porsche/VW-derived Limbach engines used on the first 50 or so Ximangos and then carried over to Rotax. They use a mechanical slider to vary resistance from low ~10 Ω at zero psi to ~180 Ω at the maximum rated pressure. A big flaw is that vibration will kill them fairly quickly, which is why there is, or should be, a dense copper sleeve added to the body. However, the remote location bolted to the firewall instead of the engine directly reduces the problem greatly. They still wear out eventually and the reading depends somewhat on system voltage. Cross-checking the gauge reading against a mechanical gauge is worthwhile. When I did so, the reading was off by a factor of two. Why? At some point, a 10 bar sender was installed; it should have been a 5 bar sender (!) for the OP gauge as factory calibrated. (It took me buying a new 10 bar sensor, then buying a new 5 bar sender to discover this.)

Shortly after getting the OP side to work, the oil temperature side of the gauge died. A new Rotax/VDO sender didn’t fix it. Simple repair of the existing gauge would require re-calibration and those values were unknown. Rotax has gone to electronic senders that plug in to their single gauges, which doesn’t solve my problem. Far better turned out to be using a new, updated Westach dual gauge, matched with their Westberg senders – calibrations known! Plus, we worked out a set match giving a much better sweep range on the dial than the original. (Westach (www.westach.com) made the original Ximango gauges).

Pete at Westach will now know how to duplicate the markings. 2020 Westach parts list:

              2DA3-3KV            $135

               399S10-1.5SS      $ 50

               387-100KV          $255

               301-KV-000         $ 15

                                             ====

                                             $455

    NEW:                         OLD:      

Finally, if you really wish to stay with VDO, this website has *everything* VDO, including the weird thread pitch versions often used by Rotax and very hard to find in the USA. Delivery was pretty fast, in spite of the distance  https://vdo-webshop.nl/en/21-sensors

 

 

[PaulM]

@HiFlite Thanks for this information. I am contemplating this upgrade on my Ximango where I don't have a lot of confidence in either the temp or pressure accuracy. What sort of wiring changes are needed to complete the upgrade? Was it relatively plug and play with the existing wiring?

[HiFlite]

On 7/22/2024 at 5:23 AM, PaulM said:

@HiFlite Thanks for this information. I am contemplating this upgrade on my Ximango where I don't have a lot of confidence in either the temp or pressure accuracy. What sort of wiring changes are needed to complete the upgrade? Was it relatively plug and play with the existing wiring?

The OT sender is the same wires, IIRC. The OP sender requires a couple of new ones. No big deal. I'll PM you with some other information.