Hey-
Having a liitle trouble tracking down a snag. R/H eng., on an Aztec, Lycoming IO-540. Oil temp red-lines within 5 mins. of run-up, oil pressure very low. Swapped out the vernatherm (twice, not the problem) Flushed the oil cooler and lines, looked for restrictions in the fittings, removed oil filter (no metal) checked scavenge screen (no metal) and did a compression test. All good, no blown jug. It's not a complicated system, but it's becoming a very frustrating one! Anybody see this before?...open for suggestions at this point. Pilot refuses to go with one engine.
Cheers
lycoming overtemp
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getmycutters
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Bullet Remington
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Re: lycoming overtemp
How low is very low on the oil pressure? Is this a newer engine that just started doing this or an older engine that has been slowly creeping the temps up and the pressure down??getmycutters wrote:Hey-
Having a liitle trouble tracking down a snag. R/H eng., on an Aztec, Lycoming IO-540. Oil temp red-lines within 5 mins. of run-up, oil pressure very low. Swapped out the vernatherm (twice, not the problem) Flushed the oil cooler and lines, looked for restrictions in the fittings, removed oil filter (no metal) checked scavenge screen (no metal) and did a compression test. All good, no blown jug. It's not a complicated system, but it's becoming a very frustrating one! Anybody see this before?...open for suggestions at this point. Pilot refuses to go with one engine.
Cheers
Were you pumping air out of the oil vent tube or the exhaust pipe during the compression check??
If the oil pressure is too low, then it stands to reason that the oil temp will climb. The speed the temp climbs will be relative to just how low the oil pressure is.
May be a bad set of bearing or excessive wear some where within the guts of the engine, Oil Pump failure?
Did you try adjusting the oil pressure up?? If so what happened to the temp??
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getmycutters
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It's an older engine...1200 hrs. The oil temp red lines quickly, then the pressure creeps down, and down. Tried cranking the pressure up...nothing. Compression was fine...valves and rings.
Thanks for the replies, think we're going to pull it and put it on a test cell. Looking like it may be something internal.
Cheers.
Thanks for the replies, think we're going to pull it and put it on a test cell. Looking like it may be something internal.
Cheers.
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Cat Driver
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Had a 1830 doing that, I suspected internal oil galley plugging.
The engine overhaul people figured that was very unlikely.
In the final analysis after engine tear down inspection....it was an oil galley plugged up....cause was switching from mineral oil after hundreds of hours to detergent oil....which was what I sort of figured caused it in the first place.
That engine ran normal until OAT got to around 25 degrees C and then it quickly had a temp increase with oil pressure decrease....each time it happened required a shut down to control the problem.
The engine overhaul people figured that was very unlikely.
In the final analysis after engine tear down inspection....it was an oil galley plugged up....cause was switching from mineral oil after hundreds of hours to detergent oil....which was what I sort of figured caused it in the first place.
That engine ran normal until OAT got to around 25 degrees C and then it quickly had a temp increase with oil pressure decrease....each time it happened required a shut down to control the problem.
The hardest thing about flying is knowing when to say no
After over a half a century of flying no one ever died because of my decision not to fly.
After over a half a century of flying no one ever died because of my decision not to fly.
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black hole
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northwings
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Everyone here talking about trying basic stuff first, i'm just wondering what grade of oil are you using? If its 15w50, i'd try switching to w100 and give that a shot first. I see the same problems with the Navajo's I repair, as soon as the OAT climbs above 15 C or so, oil temp skyrockets and pressure decreases. The change in oil solves the problem.
Nothin' beats the hobo life, stabbin' folks with my hobo knife
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getmycutters
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We need to talk. I have a 67 "C" model that I've had for the last 10 yrs. Same problem and two years ago could not take it anymore and overhauled the engine. I replaced everything except the accessory case. Problem did not go away. Oil heated psi dropped just below green in cruise and could barely keep 25 at idle and yes all basice covered.
I flew 50 hours but no improvement. I then replaced the accessory case and this fixed the pressure problem! Turns out years ago an AD required a hole to be drilled in the oil pump housing of the accessory case. Mine was drilled too large and on a bad angle that prevented the pump from moving enough oil.
Now I have 150 hours on the right engine and can keep the psi in the green no problem but while the left engine runs 185-195 cowl flaps closed in cruise the right will climb above 200 with flaps closed. I must open about half way anytime OAT above 10c. During climb right temp climbs up to about 200 while left is 150-160. After landing the right will run 200 while left is 170ish. In other words, the right is always warmer and of course the oil gets darker quicker.
I have the louvers, 20w-50, run 75degree rich of peak and keep 10qts, guages all calibrated, cowl flaps open during climb and as enter traffic pattern and left open, etc. The cyl heads also run about 20 degrees hotter on the right engine which could of course account for my higher temp. Looking through the service manual I noticed the early years of the louvers Piper only put them on the right. There might be something in the design?
I know 200 is well below the red line but is too warm and if allowed to cruise there for four hours the oil will get burned smell and will probably break down.
Howard swan
pa27@verizon.net
I flew 50 hours but no improvement. I then replaced the accessory case and this fixed the pressure problem! Turns out years ago an AD required a hole to be drilled in the oil pump housing of the accessory case. Mine was drilled too large and on a bad angle that prevented the pump from moving enough oil.
Now I have 150 hours on the right engine and can keep the psi in the green no problem but while the left engine runs 185-195 cowl flaps closed in cruise the right will climb above 200 with flaps closed. I must open about half way anytime OAT above 10c. During climb right temp climbs up to about 200 while left is 150-160. After landing the right will run 200 while left is 170ish. In other words, the right is always warmer and of course the oil gets darker quicker.
I have the louvers, 20w-50, run 75degree rich of peak and keep 10qts, guages all calibrated, cowl flaps open during climb and as enter traffic pattern and left open, etc. The cyl heads also run about 20 degrees hotter on the right engine which could of course account for my higher temp. Looking through the service manual I noticed the early years of the louvers Piper only put them on the right. There might be something in the design?
I know 200 is well below the red line but is too warm and if allowed to cruise there for four hours the oil will get burned smell and will probably break down.
Howard swan
pa27@verizon.net
Worth what you paid me for it:
1) multi-viscosity oil is good for the winter, but not so good for the summer - it thins out. When the OAT rises, run straight grade aeroshell 100wplus w/LW16072.
2) fundamentally, oil gets hot for one of two reasons:
b) the engine is creating too much heat - more than the oil cooling system was designed to dissipate. What are the CHT's compared to the cool engine? Fuel flow? Fuel burn? Power setting? Gauges/senders accurate? Or,
c) the engine is creating a normal amount of heat, but the heat in the oil simply isn't getting removed because either:
i) the oil is not getting circulated through the cooler (vernatherm closed, passages/lines blocked/collaped, cooler plugged up internally), or
ii) the cooler isn't dissipating heat, because it isn't getting air through it, because the winterization plate is on, fins are plugged up with crap, or the air simply isn't being delivered.
P.S. Any engine that runs hotter than it should, should have it's baffles looked at very carefully for leaks, cracks and missing pieces. It doesn't take much of a leak to let the air slip by without cooling the engine, and as the years go by and the baffles deteriorate ....
1) multi-viscosity oil is good for the winter, but not so good for the summer - it thins out. When the OAT rises, run straight grade aeroshell 100wplus w/LW16072.
2) fundamentally, oil gets hot for one of two reasons:
b) the engine is creating too much heat - more than the oil cooling system was designed to dissipate. What are the CHT's compared to the cool engine? Fuel flow? Fuel burn? Power setting? Gauges/senders accurate? Or,
c) the engine is creating a normal amount of heat, but the heat in the oil simply isn't getting removed because either:
i) the oil is not getting circulated through the cooler (vernatherm closed, passages/lines blocked/collaped, cooler plugged up internally), or
ii) the cooler isn't dissipating heat, because it isn't getting air through it, because the winterization plate is on, fins are plugged up with crap, or the air simply isn't being delivered.
P.S. Any engine that runs hotter than it should, should have it's baffles looked at very carefully for leaks, cracks and missing pieces. It doesn't take much of a leak to let the air slip by without cooling the engine, and as the years go by and the baffles deteriorate ....
