Oil temperature/pressure fluctuations

Hi Walter,

what type of instrumentation are you running please? also do you have an external alternator fitted as well as the internal one?

Regards,

Byron.

That sounds like you have a bad ground from the battery or charging circuit. I would carefully inspect the wires and crimps and look for corrsion under and of the connections.

You could always use a voltmeter to measure the voltage from from the battery -ve to the ground connection on each instrument. Switch on as many loads as you can to draw a high current, this will reveal the fault more quickly. You should have very little volt drop between the grounds, less than 100mV.

If all the affected circuits are on the same fuse then the fault could be in the +ve supply path. You will just have to check that instead.

Walter, Recently I had a similar erratic instrument reading problem and eventually discovered the earth terminal for the engine instruments had come loose just enough to make contact but loose enough for the erratic readings.  Simply tightening that earth terminal bolt fixed the problem. John Harris Rotax 914.

I am running GRT EIS engine monitor ... and no I don't have an external alternator.

I think this has something to with EIS ground cause I also noticed ( in the engine logs that I record ) that the outside temp probe readings seemed to get stuck at around 75 F recently regardless of the actual outside temp ( which yesterday was closer to 65 F)

Thanks

I'm with Kevin. I think you have a ground issue. Start at the battery and tighten all your grounds in the engine compartment and the instrument panel. I had an issue like this many years ago on the oil pressure. The pressure fluctuated like your when the throttle was advanced and went back to normal when pulled back to idle.  Even though my meter said I had a ground it was poor. I installed a new wire and problem solved.