Advice on an O-300 with oil pressure issues (sad story)
- Thread starter DE727UPS
- Start date
rframe
pǝʇɹǝʌuı
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.
Roger Roger
Bottom of the list
DE727UPS
Well-Known Member
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.
Roger Roger
Bottom of the list
Bummer
Roger Roger
Bottom of the list
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.
pnwchief22
Well-Known Member
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.
knot4u
Repeat Offender
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.
drunkenbeagle
Gang Member
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.
pnwchief22
Well-Known Member
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.
knot4u
Repeat Offender
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.
drunkenbeagle
Gang Member
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.
pnwchief22
Well-Known Member
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.
O300runner1
Well-Known Member
I made this account because of this thread and would like to give some information I've learned. Hopefully someone will see the information I have to offer and benefit from my struggle.
1. Check the gauge for accuracy
2. Check the line for damage or leaks
3. Check the fittings for debris and damage
4. Check the oil screens - both of them for debris and damage
5. Check the bypass valve for damage and debris - replace the spring regardless. (You can also leave the valve off and turn the prop by hand until oil comes out before going deeper (remove all spark plugs))
6. Check the pump gears for wear - you can remove the tach cable housing and check for play in the gear.
7. Remove valve covers - you're looking for even distribution of oil on the springs and the rocker arms.
8. Remove a cylinder - inspect the crank case for any cracks in the oil channels and any loose or missing parts.
9. Disassemble engine - going through all the other steps then it's time for an I.R.A.N. - look for excessive wear and any damage.
Brown stains are a sign of oil being cooked on the location and no oil flow over that particular spot.
In my situation, Joe Shmo did the "Major O/H". He overtorqued the fwd thru bolts and pinched the cam. Sending metal through the engine and destroying the oil pump gears and housing. The excessive metal in the oil well past break in was a sign, but tearing down the engine confirmed it.
I belive that the following information needs to be well known to avoid overpaying for aircraft and for the safety of pilot's:
Continental's manual M-0 outlines the basic Information needed for an O/H including required replacement parts. THRU BOLTS ARE REQUIRED TO BE REPLACED AT MAJOR O/H'S. You can look in the nose bowl and see if they are nice and new. ALL ACCESSORIES ARE REQUIRED TO BE REPLACED AT MAJOR O/H'S. You can look through the logbook. DO NOT BUY AN AIRCRAFT WITH POSTED LOW TIME S.M.O.H. UNLESS YOU VERIFY IT HAS BEEN DONE PROPERLY. There is more information in M-0, but if everyone knows to look for the obvious ones, then the hack mechanics will hopefully stop cutting corners.
1. Check the gauge for accuracy
2. Check the line for damage or leaks
3. Check the fittings for debris and damage
4. Check the oil screens - both of them for debris and damage
5. Check the bypass valve for damage and debris - replace the spring regardless. (You can also leave the valve off and turn the prop by hand until oil comes out before going deeper (remove all spark plugs))
6. Check the pump gears for wear - you can remove the tach cable housing and check for play in the gear.
7. Remove valve covers - you're looking for even distribution of oil on the springs and the rocker arms.
8. Remove a cylinder - inspect the crank case for any cracks in the oil channels and any loose or missing parts.
9. Disassemble engine - going through all the other steps then it's time for an I.R.A.N. - look for excessive wear and any damage.
Brown stains are a sign of oil being cooked on the location and no oil flow over that particular spot.
In my situation, Joe Shmo did the "Major O/H". He overtorqued the fwd thru bolts and pinched the cam. Sending metal through the engine and destroying the oil pump gears and housing. The excessive metal in the oil well past break in was a sign, but tearing down the engine confirmed it.
I belive that the following information needs to be well known to avoid overpaying for aircraft and for the safety of pilot's:
Continental's manual M-0 outlines the basic Information needed for an O/H including required replacement parts. THRU BOLTS ARE REQUIRED TO BE REPLACED AT MAJOR O/H'S. You can look in the nose bowl and see if they are nice and new. ALL ACCESSORIES ARE REQUIRED TO BE REPLACED AT MAJOR O/H'S. You can look through the logbook. DO NOT BUY AN AIRCRAFT WITH POSTED LOW TIME S.M.O.H. UNLESS YOU VERIFY IT HAS BEEN DONE PROPERLY. There is more information in M-0, but if everyone knows to look for the obvious ones, then the hack mechanics will hopefully stop cutting corners.
O300runner1
Well-Known Member
I forgot to mention AD 72-25-02. Hopefully the photo is clear enough. The one at the top of the photo is the new design and the other is the old or original. Removing the tach cable housing from the accessory case will let you see the slotted part of the gear. It should end before the shelf, otherwise the AD was never complied with. The seal for the tach cable housing should be installed with flat side down when pressing it into the housing. You should be able to see the inside of the seal while looking at the mounting face of the housing. You'll have oil in your tach cable if it's backwards, and it can work its way to the gauge.
Attachments
Serious question (no intention to be snide): Have you definitively determined that, in fact, there actually IS no oil pressure?
knot4u
Repeat Offender
Yes.