Oil pressure problems--Total Whitewash.
in 912 / 914 Technical Questions
13 years ago
Greetings all,
Here's my dilemma. I am an LSRM-A working on an SLSA. I've got a somewhat older (~2007 vintage) Rotax 912ULS with a VDO-style oil pressure sensor and a TL Elektronik engine monitor. The pressure sensor is mounted directly to the oil pump housing.
This engine is showing fluctuating oil pressure. The pressure will fluctuate in and out of the acceptable range, as in 45, 52, 53, 102, 44, 23, 97... numbers in PSI.
There are several places I can think of to find the problem.
I've watched the video on this site on the subject, and it describes removing both the electric sensor and the pressure relief valve. The video leaves out what I consider to be VITAL information: Should you purge the oil system after either one of these services?
My money is on the sensor. I've replaced one of these sensors before (and performed the purge procedure just in case), but the only sensor available now is the Honeywell variable current styel sensor. That P.O.S. TL engine monitor has a password that nobody knows, so I can't get into it to change the settings. According to SI-912-020, the resistive-type VDO sensor "...is not suitable anymore." In context, this is a very vague statement. Does this mean that VDO sensors are no longer authorized for use on 912's, or that VDO sensors aren't compatible with the wiring for Honeywell-equipped engines? Can I legally replace this VDO sensor if I manage to find an identical unit, or must I install a Honeywell sensor? If I have to use a Honeywell sensor, it means a new engine monitor.
I doubt the issue is caused by engine vibration, but it's a plausible reason for the early failure. I'll have to talk with the airframe manufacturer about moving the sensor to the firewall. I have a temporary mechanical gauge, so I can do that check if need be.
So, to recap: Should I purge the oil system after removing the sensor, relief valve, or both? And can I install a new VDO sensor if I find one?
Thanks in advance,
Adam
LSRM-A CFI-SP
Here's my dilemma. I am an LSRM-A working on an SLSA. I've got a somewhat older (~2007 vintage) Rotax 912ULS with a VDO-style oil pressure sensor and a TL Elektronik engine monitor. The pressure sensor is mounted directly to the oil pump housing.
This engine is showing fluctuating oil pressure. The pressure will fluctuate in and out of the acceptable range, as in 45, 52, 53, 102, 44, 23, 97... numbers in PSI.
There are several places I can think of to find the problem.
I've watched the video on this site on the subject, and it describes removing both the electric sensor and the pressure relief valve. The video leaves out what I consider to be VITAL information: Should you purge the oil system after either one of these services?
My money is on the sensor. I've replaced one of these sensors before (and performed the purge procedure just in case), but the only sensor available now is the Honeywell variable current styel sensor. That P.O.S. TL engine monitor has a password that nobody knows, so I can't get into it to change the settings. According to SI-912-020, the resistive-type VDO sensor "...is not suitable anymore." In context, this is a very vague statement. Does this mean that VDO sensors are no longer authorized for use on 912's, or that VDO sensors aren't compatible with the wiring for Honeywell-equipped engines? Can I legally replace this VDO sensor if I manage to find an identical unit, or must I install a Honeywell sensor? If I have to use a Honeywell sensor, it means a new engine monitor.
I doubt the issue is caused by engine vibration, but it's a plausible reason for the early failure. I'll have to talk with the airframe manufacturer about moving the sensor to the firewall. I have a temporary mechanical gauge, so I can do that check if need be.
So, to recap: Should I purge the oil system after removing the sensor, relief valve, or both? And can I install a new VDO sensor if I find one?
Thanks in advance,
Adam
LSRM-A CFI-SP
