Advice on an O-300 with oil pressure issues (sad story)

I have first person experience with the aircraft being discussed. It has stc Electronic Oil pressure and oil temp guages. Transducer and associated flex hose was the first thing tested. Confirmed good, not the failure….Mid America A/P IA providing excellent service, especially considering his business is hopping and he is out twice a month maintaining warbirds. Substitute guage confirmed no pressure. Fresh oil with two new oil pump gears in the overhauled accessory case, same result. Screens clear.


Well sounds like he doesn't need our help then :p
 
Shrug. Seen lots of wires and pressure senders go wonky, never seen a direct reading oil pressure gauge quit or even be significantly out of cal.

Had the hard line feeding the oil pressure gauge in a Cessna fatigue break and pump oil into the cockpit, thankfully it was during taxi and not in flight. Have read of this happening several times on other airplanes.
 
No. It's been a first owners/non-pilots nightmare. The other co-owner is on here. I haven't heard much lately but I think they ended up just overhauling it. The numbers were good on paper prior to buying it. They got a great deal on a 172 with a 400 hour engine. Did a pre-purchase. Did all the right things the way I see it. And it's been a disaster. Could have happened to me. I've bought planes on a general feeling without doing a pre-purchase a few times. I've been lucky.
 
No. It's been a first owners/non-pilots nightmare. The other co-owner is on here. I haven't heard much lately but I think they ended up just overhauling it. The numbers were good on paper prior to buying it. They got a great deal on a 172 with a 400 hour engine. Did a pre-purchase. Did all the right things the way I see it. And it's been a disaster. Could have happened to me. I've bought planes on a general feeling without doing a pre-purchase a few times. I've been lucky.
Bummer :(
 
Had the hard line feeding the oil pressure gauge in a Cessna fatigue break and pump oil into the cockpit, thankfully it was during taxi and not in flight. Have read of this happening several times on other airplanes.
Makes sense that that happens, and I’m not saying it can’t, just that i never had it in the tens of thousands of airplane hours I was taking care of Cessnas, pipers, and beavers.
 
New oil pump gears and repaired the oil sump & accessory case while off the plane. Service bulletin issued in 1996 addressed some of the pressure indication.
Does the O-300 have the same issues as the O-200 regarding the oil pump? I had a friend with a C-150 that would sometimes lose prime for the pump if it was parked at the wrong angle (AOA, and that just happened to be the angle of his hangar floor). He was finally able to get it fixed by changing the gears and the oil pump housing if I recall correctly.
 
New oil pump gears and repaired the oil sump & accessory case while off the plane. Service bulletin issued in 1996 addressed some of the pressure indication.

Took 2 months? Shop schedule checks out.

My new mantra is fix it yourself, and then wait on an A&P to get the logbooks singed. Not any faster, but at least you know it is going to work after the ink is dry.
 
Does the O-300 have the same issues as the O-200 regarding the oil pump? I had a friend with a C-150 that would sometimes lose prime for the pump if it was parked at the wrong angle (AOA, and that just happened to be the angle of his hangar floor). He was finally able to get it fixed by changing the gears and the oil pump housing if I recall correctly.
I cannot say with any confidence that this was similar to the O-200 oil issue ( I owned two 150’s and never had a priming issue with those). This particular O-300 accessory case and oil pump appears to have been re-installed in field after the engine came back from signature in the early 2000’s. The documentation from those logbook entries and 337 is less than perfect.
 
Took 2 months? Shop schedule checks out.

My new mantra is fix it yourself, and then wait on an A&P to get the logbooks singed. Not any faster, but at least you know it is going to work after the ink is dry.
Singed? I don't know what A/Ps you know that just sign off work they either didn't witness or complete themselves. I'm going to go find a CFI to sign off a BFR post haste.
 
Singed? I don't know what A/Ps you know that just sign off work they either didn't witness or complete themselves. I'm going to go find a CFI to sign off a BFR post haste.

I have supervision and talk to someone before doing anything. Most of the effort is often finding out what's wrong in the first place though. Part 43 appendix A(c) encompasses a whole bunch.
 
I cannot say with any confidence that this was similar to the O-200 oil issue ( I owned two 150’s and never had a priming issue with those). This particular O-300 accessory case and oil pump appears to have been re-installed in field after the engine came back from signature in the early 2000’s. The documentation from those logbook entries and 337 is less than perfect.
It was fitted with a newer sump prior to the engine installation in 2022. It is flying again with normal indications on the same electronic guages.
 
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