I am getting wildly fluctuating oil temp indications on my EMS D10. Engine off reading is steady. After engine start temp swings 2 or 3 degrees centred around 30. The variation increases as oil temp increases until at normal operating temp the swing is from 90 up to 150. I borrowed a new sensor but problem still existed. Also checked wiring at sensor -- looks ok. Loaded latest firmware as well. Have had 300 odd hours up and problem started about 20 hours ago. Any suggestions?