Encore Driver

I paid $200k for my "97 Encore two years ago. It has the GTN 750 but not the long range tanks with 635 hours. I thought it was worth the money then and still do. But it probably takes a special buyer to see the value, the need to go fast and high and since I was looking for the last aircraft I'll ever need to buy I was willing to pay for exactly what I wanted.

I may have found the remedy to this problem. The ship oil pressure sending unit is mounted at the lowest point possible within the cowling, when the mechanic installed the JPI oil pressure sending unit it was installed higher up on the engine mount. I wondered if it was possible that when the engine was shut down and the oil was thin it was backflowing into the crankcase since the sending unit was above the level where the oil line exited the case. This could allow an air bubble to form next to the sending unit, even though I had bled the air from the line previously. So I moved the JPI sending unit to the lowest point possible and bled the line again. So far the fluctuation in oil pressure are minimal( +-2PSI). I have flown about 10 hours since the change, hope that's all it was. Steve

The ships oil temp gauge reads from the back of the engine right after the oil cooler and I run it about 150 degrees. The JPI reads from the front of the engine before the oil cooler and it reads 190 degrees. Both of them are stable and are controllable via the cowl flaps.

Anybody else notice oil pressure fluctuations of +or- 5 PSI on TSIO-360-MB engine? My 1997 M20K Encore has done this for more than 300 hours. Installed a JPI engine monitor and it reflects the same condition. The ship gauge reads 50 PSI normally but will momentarily read anywhere from 45 to 55 PSI. The JPI normally reads 40 PSI and will fluctuate between 35 to 45 PSI. This is a continual fluctuation not a once in a while thing. I have asked the mechanics at the last 2 annuals and they have no advice. The only idea I've heard that makes sense is that the automatic waste gate for the turbo uses oil pressure from the same line that both of the oil pressure sending units are installed in so the fluctuations are generated from the waste gate movements. If others have noticed this I can let it rest. Thanks Steve

I followed your advice and sent the motor to Bobbie Eldridge at Globe Motors Inc. Waiting to hear what they found. The arm that was attached to the cowl flap motor evidently had roll pins that were too short and the motor shaft had spun inside the arm at some time in the past. This had been repaired with longer roll pins but it was not a tight connection. I'm not sure that larger diameter roll pins with the -513 motor will completely fix it. Seems like in your post you had priced the arm? If so was it from Mooney? Thanks Steve

Is the cowl flap system on the 1997 Encore supposed to be adjustable throughout it's entire range? Mine will hold in the closed position and hold in the open position but if it is set any other place it slowly bleeds to the about half open. Every 10 minutes or so it needs reset to maintain oil temp. Is this normal for this system? If not, I'll have the motor rebuilt. It currenly has a Globe Motor 880050-505 cowl flap motor and in speaking to Globe they now have an 880050-513 motor. Are they interchangeable? Steve

I've read this thread with interest since I have a question about my cowl flap motor. The motor works but does not hold position. It slowly bleeds off to about half open unless I select full closed or full open. I have to reset it about every 10 minutes in flight to keep the oil temp where I want it. Is this normal for this system or should I have it rebuilt? Steve