Greetings,
I have experienced a sudden onset of oil pressure fluctuation. Normally, I would read a steady 4.8 kpa in cruise @2900 rpm. In today’s flight, I saw rapid fluctuations in oil pressure during cruise. It would drop to 3kpa in about 1-1/2 seconds. If I lowered the rpm it resumed back quickly to 4.8. Resuming hold @ 4.8 kpi, but it occurred again. I checked the oil level and it was at the minimum line of the dip stick. After adding oil, I saw fluctuations after climb out when I throttled to cruise configuration of 2900 RPM with CHT’s at 250 F and EGT in the 1250’s F. It also fluctuated when I encountered turbulence, it was small movements as compared to the aforementioned. It eventually maintained a steady 4.8 kpa for the rest of the 15 min flight. Any recommendations on what I should look at; oil pump, electrical, possible metal fines causing blockage, pressure relief valve, etc?
2200 serial number 22A981.
Thanks!
Alex R.
Hello Alex,
The best way to check is to use a mechanical guage in the engine to confirm the pressure issue. That seems a bit hard as the pressure drop sounds intermittent. So I would change the oil pressure sender first. It is not unheard of for them to fail after some time in service.
I had a similar problem. New oil pressure sender fixed the problem on my GEN 2 3300. Nick at Arion Aircraft sells a kit to mount the VDO sender on the firewall which is reported to mitigate the problem.
BTW - mine was spiking up from about 50 pounds to 75-80 pounds.
John McGlynn
I had a similar problem. New oil pressure sender fixed the problem on my GEN 2 3300. Nick at Arion Aircraft sells a kit to mount the VDO sender on the firewall which is reported to mitigate the problem.
BTW - mine was spiking up from about 50 pounds to 75-80 pounds.
It wasn't the new pressure sender that fixed the problem, it was the new sender that showed that the problem was in the sender 🙂
Hi. I have noticed something similar over the last few months. Jabiru 2200 year 2008. Oil pressure is generally around 3,7-3,8 bar when in cruise at 85 deg C, but when reducing throttle from cruise setting, I see the pressure jump up for a second or two to 4,1-4,2 bar, and then drop to what I consider normal pressure again. At idle rpm I have approx. 1,5-1,7 bar.
I have got a MGL EFIS where the oil pressure is indicated. I guess the screen might have some delay, so what the pressure spike might be I don't know. But if it is the sender being faulty, I believe my oil pressure is fine. I just need a new sender.
Continue to see these eratic pressure spikes, so I have decided to replace the sender. I remove the old VDO sender to verify the model and find there is a small fiber gasket between the sender and the engine. The gasket is brittle and now broken to pieces. Does a new VDO sender come with a new seal? If not - what will fit?
@olpo That doesn't sound like a standard jabiru oil pressure sensor. The jabiru oil pressure sensor uses a 1/8 NPT taper thread.
Hi. I have noticed something similar over the last few months. Jabiru 2200 year 2008. Oil pressure is generally around 3,7-3,8 bar when in cruise at 85 deg C, but when reducing throttle from cruise setting, I see the pressure jump up for a second or two to 4,1-4,2 bar, and then drop to what I consider normal pressure again. At idle rpm I have approx. 1,5-1,7 bar.
I have got a MGL EFIS where the oil pressure is indicated. I guess the screen might have some delay, so what the pressure spike might be I don't know. But if it is the sender being faulty, I believe my oil pressure is fine. I just need a new sender.
I have pressure jumps too, and I don't see it as a problem. If the pressure does not drop, it would be a problem.
With the VDO analog pressure indicator connected I see no spikes on the oil pressure. But when connected to my MGL Extreme EFIS I about a year ago started having pressure spikes up to 4.2 bar followed by a drop to lower than average. Most of the time it is saying 3.6-3.7 bar which is also 0.5 higher than what the VDO indicator says.
The oil pressure provide by the jabiru oil pump is not a perfect steady pressure it does have some a wave form if measured using a high speed pressure sender. What we have seen happen is that the device reading the pressure signal is fast enough it can pick up on some of the higher pressure points of the pressure signal.
