Oil Pressure Transducer Failure Indication

Yesterday I changed the oil and filter on my IO-360 and then ran up the engine to check for leaks. Oil pressure looked fine on start-up but during run up the oil pressure went up to 99 psi. A little later it was down to 70 psi, which is about normal. Oil temperature was right where I would expect it to be given OAT and run time.

Seems like there would be three failure modes for the circuit:

1) transducer failure
2) open circuit
3) short/ground

What would the readout on the EIS-4000 be for each case? An open circuit on the temperature probes shows up as "59" degrees, but what the listed faults look like?

Bubblehead said:

Yesterday I changed the oil and filter on my IO-360 and then ran up the engine to check for leaks. Oil pressure looked fine on start-up but during run up the oil pressure went up to 99 psi. A little later it was down to 70 psi, which is about normal. Oil temperature was right where I would expect it to be given OAT and run time.

Seems like there would be three failure modes for the circuit:

1) transducer failure
2) open circuit
3) short/ground

What would the readout on the EIS-4000 be for each case? An open circuit on the temperature probes shows up as "59" degrees, but what the listed faults look like?

Click to expand...

Had the same issue ... its the probe, ours failed at 500 hours.

Mine just failed at a little over 200 hours. I was in cruise at 11000 feet and slowly watched it climb to 95 and then back to 90 for a while, and then finally to a normal pressure reading (75). Changed the sensor and on repeats.

Vic

This one has 85 hours on it. I'll email GRT Tonight. Thanks for the info.

Transducers

Bubblehead said:

Yesterday I changed the oil and filter on my IO-360 and then ran up the engine to check for leaks. Oil pressure looked fine on start-up but during run up the oil pressure went up to 99 psi. A little later it was down to 70 psi, which is about normal. Oil temperature was right where I would expect it to be given OAT and run time.

Seems like there would be three failure modes for the circuit:

1) transducer failure
2) open circuit
3) short/ground

What would the readout on the EIS-4000 be for each case? An open circuit on the temperature probes shows up as "59" degrees, but what the listed faults look like?

Click to expand...

VDO used to make good products. My fuel pressure sensor started giving false readings after about 50 hrs. I replaced it with the $$$high dollar$$$ one from GRT and it has been rock solid since.

You can cross reference the GRT part number and buy from Digi-Key or some other electronic supplier and save five or ten dollars, but why not support the great guys that supply us with some of the greatest electronic gadgets the experimental aviation community has ever seen????

Info from GRT

I emailed GRT Sunday night and got this response from Tim Martin.

"A high reading can be caused by a poor ground to the sensor. This is most likely to affect the oil pressure sensor, as the case of this sensor must be tied to ground, but can pick up a poor ground through its hose which connects it to the engine. You can test it by grounding the case of the sender and observing the reading on the EIS.

Check that the connectors are in good condition, and secure. If you have serviced the sender, make sure that no sealant or tape was used on the threads of the sender.

Long story short, loss of ground on that sender = high reading."

I'll check the connections and report back.

I agree with mannanj about supporting good suppliers. GRT has been very helpful and if I need to change senders and if it is out of warranty I'll buy from them.