Oil Pressure Sensor

[Tbass2020]

Hi All, I have been noticing that upon starting my engine my oil pressure sometimes takes a bit of time to show pressure. Then when it does it goes crazy for a few minutes and seems settle down once the engine has warmed up. A few times it's gone out while in flight.  Ive read that it could be the sensor but I was also curious what would happen if the sensor setting on the Dynon 120 was set to the wrong sensor example it's at 1 when it should be 4. What type of issue would that cause?

Thanks in advance!

[Tom Baker]

I think a wrong setting in the Dynon will either make it not work or provide the wrong range to be displayed. If it is a VDO sender I would just replace it.

[ibjet]

I had my oil pressure reading go bonkers on me before, similarly to your experience. It turned out the be the gauge itself. Roger Lee advised at the time that the senders very rarely go out. I bought a new gauge from Aircraft Spruce, but found out the the original Mfr overhauls the oil pressure gauges and temperature gauges quite reasonably. My CT is a 2006, so not sure if the gauge story would be the same on yours. I will look up the company name and phone number that I have and get back to you right away. 

[ibjet]

The Mfr of my gauges (2006 CTSW) was UMA Instruments. There Ph# is 540-879-2040.Very reasonably priced and nice to work with. 

[Tom Baker]

He has a Dynon, not an analog gauge. Sending unit do fail on a regular basis. I used to have a rig set up to test them, now I just replace. If the new unit doesn't fix the problem I can always switch back to the old sender. Failures are so common that I started keeping a spare VDO sender in inventory. I have not replaced many of the later style sending units.

[Tbass2020]

Thanks everyone. Will try the sender route and let you know how it goes. 

[Tom Baker]

Tbass2020, which model airplane and what year model do you have? Is your sender mounted in the original location or remote mounted?

[Tbass2020]

I have a 2008 CTLS. I am not sure inn the mount we have never moved it before son I assume original place when it was manufactured. 

[Tom Baker]

2008 should have the VDO sending unit. The original location is on the right side opposite the oil filter. If it has a brass ring on the base it is original. If mounted in the original location you need a VDO 360-004.

[Tbass2020]

Tom appreciate that was just with my mechanic and yes that is the exact location. So you think it’s a bad sender then?  Why that particular one?  Appreciate all the help!!

[Tom Baker]

The senders fail due to vibration. There two things you can do to help the senders. the first is remote mounting the sending unit. This requires a different sender with 2 terminals, with one going to ground. The other thing is keeping the carbs balanced. A quick indicator that you may need a carb balance is watching your throttle lever, especially at idle. If it has a significant vibration or buzzing, you may need to balance the carbs. 

[sandpiper]

I have replaced two sensors in the 12 years and 650 hours on my plane. Like Tom, I keep a spare sensor. They are cheap.

The first time this happened I traced all connections, cleaned them, and secured them. Although it could be a wiring issue, in my failures replacing the sender fixed it immediately. When they fail, at least in my case, they were erratic. The needle didn't just drop to zero and stay there.

[Tbass2020]

John, thanks for your input as well. That is similar to mine it will go to 140 in a second then settle back in range. Have a new sender being ordered per Tom's recommendation above. Thanks again can't wait or get back up in the air!