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Oil temperature too high... Problem?
- Thread starter belisle
- Start date
Ursa Major
Registered User
Coeur d'Alene, Idaho
AkPA/18 said:
Mark,
Its still running right around 200 degrees but I haven't had the chance to fly it at much more than 65 degrees OAT. The forecast for this weekend looks like high 70s or low 80s. I'll see what kind of temps I get with low speed climbs.
We did a couple of different things including changing the vernatherm. Not sure if that was the cure. The installation of a remote oil filter probably helped too. I'm not too concerned with the temps we get up here - but I might be a little leery if I lived in Arizona or Oklahoma and had to deal with 100+ OAT temps.
belisle
Registered User
Quebec, CANADA
Installed the oil cooler 3 inches aft of cylinder #4
I have installed the oil cooler at 3 inches aft of its previous position at the back of the #4 cylinder. I made a couple of flight since that time and notice that the oil temp was at 225 to 230 deg. while the OAT was indicating 58 to 60 at 2500 ft. The temperature was in the green arc of my gauge where the limit is at 245. I would prefer to have it lower around 200 to 210 but I still do not know what to do to lower this oil temp. I run the engine at 2350 with a Borer prop 82/43 and EDO 2000 floats. Indicated airspeed 80 mph at full gross weight. Any help will be appreciated.
Bernard.
I have installed the oil cooler at 3 inches aft of its previous position at the back of the #4 cylinder. I made a couple of flight since that time and notice that the oil temp was at 225 to 230 deg. while the OAT was indicating 58 to 60 at 2500 ft. The temperature was in the green arc of my gauge where the limit is at 245. I would prefer to have it lower around 200 to 210 but I still do not know what to do to lower this oil temp. I run the engine at 2350 with a Borer prop 82/43 and EDO 2000 floats. Indicated airspeed 80 mph at full gross weight. Any help will be appreciated.
Bernard.
Steve Pierce
BENEFACTOR
Graham, TX
If it were me I would get a 62417 oil cooler bypass plug, 69436 oil cooler bypass spring and a 62415 oil cooler bypass plunger and replace the vernitherm with these parts. They will let the oil through the cooler as soon as it gets warm enough to thin out. You should not have that high of an oil temp with those OATs. It has to be an engine problem or oil delivery through the cooler. I will see if I still have the above parts if needed.
belisle
Registered User
Quebec, CANADA
No Vernitherm
Steeve: I was told by the engine shop that I do not have any vernitherm on this engine. The change on the position of the cooler (3 in. aft of the cylinder) did not change very much the temperature. Could you tell me what is the size of the holes on the nose bowl. When rebuilding the bird I change it for an other one (used but in better condition than mine) and I am not sure for what model of Piper it was coming from. I had to adapt it to the cowlings with some adjustments. Maybe the holes are smaller than the required ones??
Bernard
Steeve: I was told by the engine shop that I do not have any vernitherm on this engine. The change on the position of the cooler (3 in. aft of the cylinder) did not change very much the temperature. Could you tell me what is the size of the holes on the nose bowl. When rebuilding the bird I change it for an other one (used but in better condition than mine) and I am not sure for what model of Piper it was coming from. I had to adapt it to the cowlings with some adjustments. Maybe the holes are smaller than the required ones??
Bernard
skysigns
FRIEND
Yelm WA 98597
oil
if it helps piper had a #SB about using 2 coolers the panwee 150 installed one under the right front baffling as well is in the nose bowl varitherm in some of the older 0320 was a spring and ball that pushed a sleave the sleave might be sticking on your bottom cowl you can existent the lip about 2" to draw more air threw the cowling i have a 12 i am rebuilding now that has the same problem it stays on floats i should have it flying in the spring let me know how yours comes out
if it helps piper had a #SB about using 2 coolers the panwee 150 installed one under the right front baffling as well is in the nose bowl varitherm in some of the older 0320 was a spring and ball that pushed a sleave the sleave might be sticking on your bottom cowl you can existent the lip about 2" to draw more air threw the cowling i have a 12 i am rebuilding now that has the same problem it stays on floats i should have it flying in the spring let me know how yours comes out
S
StewartB
Light Plane Maintenance had an interesting article about high oil temps a couple of months ago. They mentioned the normal things, like baffles, incorrectly seating Vernatherms, etc. One case they discussed was caused by insufficient bearing clearances. The oil cooler couldn't overcome the increased heat caused by reduced oil flow (not oil pressure) and tight bearings. The engine was torn-down and the bearing clearances corrected, and the problem went away.
Who did your major, and did they check the clearances? Make sure you're treating the problem, not just the symptoms.
SB
Who did your major, and did they check the clearances? Make sure you're treating the problem, not just the symptoms.
SB
Fortysix12
Registered User
RanchAero Grand Vista, Brooksville
Vernatherms close to do there job not open. That's why they need to be 100 percent and varified. Visually. And changing one used one with with a another used one can be a waste of time. When trouble shooting oil temps you have to varify with absolute certainty that all parts are doing there job. No exceptions! This means observing the full function of the part closing and opening in a pot of boiling water installed in the oil filter adapter. I have had a brand new therm not function.
leon tallman
Registered User
temple hills md
oil temp
I think your problem is that prop. the 172's have the same engine and oil cooler the citarbia's also and no problem the diff is about 20 to 30 mph in airspeed. so you don't get the same airflow. i hope you get this worked out as I have the same problem. i'll be watching
I think your problem is that prop. the 172's have the same engine and oil cooler the citarbia's also and no problem the diff is about 20 to 30 mph in airspeed. so you don't get the same airflow. i hope you get this worked out as I have the same problem. i'll be watching
mvivion
FOUNDER
Bozeman,MT
The problem isn't the prop. And he said he doesn't have a vernatherm. As someone pointed out, that is way too hot an oil temp for a Cub, even if you had a different nose cowl. Remember, virtually all the Pipers had similar sized engines, so the air inlets should be just fine.
Are your cylinder head temps high as well?
As advised, I'd start taking a close look at the engine's internal working parts. As Stewart noted, you may be trying to treat the symptoms, instead of the problem.
In temps that you describe, on floats, I expect to see oil temps running around 170 to 180 F. Your temps sound WAY too high, and I doubt it's the cooler causing the whole problem.
Get a good wrench to start looking carefully at your engine. There could be something wrong in there that could cost you a lot if left unresolved.
MTV
Are your cylinder head temps high as well?
As advised, I'd start taking a close look at the engine's internal working parts. As Stewart noted, you may be trying to treat the symptoms, instead of the problem.
In temps that you describe, on floats, I expect to see oil temps running around 170 to 180 F. Your temps sound WAY too high, and I doubt it's the cooler causing the whole problem.
Get a good wrench to start looking carefully at your engine. There could be something wrong in there that could cost you a lot if left unresolved.
MTV
mvivion
FOUNDER
Bozeman,MT
Bernard,
Oh, yeah: I just noted that your mechanic did a differential compression check on your cylinders. What I had recommended is an AUTOMOTIVE compression test. This test is recommended by Lycoming for trouble shooting cylinder problems, and used to be pretty standard, but lately has been replaced by the differential test.
The differential test only tests the cylinder's ability to HOLD pressure at one spot in its' stroke. The Automotive compression test, on the other hand, evaluates the cylinder's ability to MAKE compression, not hold pressure. That is a very fundamental difference.
My engine which I learned this on was running very high oil temps, in the range that you list: 230 or so, even on cool days. Cylinder head temps were over 400 as well, but well under red line. We couldn't find any problems on this 400 hour engine.
Finally called Lycoming and they said to do the automotive test. Two cylinders were allowing severe blow-by, heating the oil. This also results in pretty black oil pretty fast.
There's one more possibility that nobody has listed yet. I don't have my Lycoming books here, but if that engine is one that has had a constant speed propeller on it at some time, it is possible that when they removed the prop governor, they didn't put the plugs in where they should have. That's a long shot, but I've seen two Cubs (both sold rebuilt by the same company) which had engines removed from a Twin Comanche. The outfit had rebuilt the engines, but didn't make the appropriate changes to accomodate the removal of the prop governor. This bypasses the oil from parts of the engine and causes oil temperatures in the range you describe.
Ask your mechanic to check to verify that your engine does not have a provision for a governor. If it does, this is a possibility, and the engine oil temps will run pretty hot, since the oil isn't circulating properly.
MTV
Oh, yeah: I just noted that your mechanic did a differential compression check on your cylinders. What I had recommended is an AUTOMOTIVE compression test. This test is recommended by Lycoming for trouble shooting cylinder problems, and used to be pretty standard, but lately has been replaced by the differential test.
The differential test only tests the cylinder's ability to HOLD pressure at one spot in its' stroke. The Automotive compression test, on the other hand, evaluates the cylinder's ability to MAKE compression, not hold pressure. That is a very fundamental difference.
My engine which I learned this on was running very high oil temps, in the range that you list: 230 or so, even on cool days. Cylinder head temps were over 400 as well, but well under red line. We couldn't find any problems on this 400 hour engine.
Finally called Lycoming and they said to do the automotive test. Two cylinders were allowing severe blow-by, heating the oil. This also results in pretty black oil pretty fast.
There's one more possibility that nobody has listed yet. I don't have my Lycoming books here, but if that engine is one that has had a constant speed propeller on it at some time, it is possible that when they removed the prop governor, they didn't put the plugs in where they should have. That's a long shot, but I've seen two Cubs (both sold rebuilt by the same company) which had engines removed from a Twin Comanche. The outfit had rebuilt the engines, but didn't make the appropriate changes to accomodate the removal of the prop governor. This bypasses the oil from parts of the engine and causes oil temperatures in the range you describe.
Ask your mechanic to check to verify that your engine does not have a provision for a governor. If it does, this is a possibility, and the engine oil temps will run pretty hot, since the oil isn't circulating properly.
MTV
S
StewartB
Here's something to read. Not the LPM article I referred to, but similar.
http://www.avweb.com/news/maint/182617-1.html
SB
http://www.avweb.com/news/maint/182617-1.html
SB
belisle
Registered User
Quebec, CANADA
Oil temperature too high...
I have called Lycoming and explained my problem and the technician told me that if the oil temperature was in the range of 230 to 245 and over and the oil pressure was in the green arc from 50 to 85 psi the problem would certainly be at the gauge. Even if the gauge was looking to be OK with boiling water he told me that it had already happend that in the high range it could be defective. He told me also that when the oil temperature is going higher the oil pressure is going lower as much as 20 psi and in the yellow arc. He told me to use an infrared heat temperature gun and direct it on the oil pressure screen near the magnetos just after landing to check if the temperature would be about the same + or - 5 degrees by comparison with the gauge. I have read the article posted by Stewartb on avweb and I will double check everything they suggest to do. The technician also told me that the magic number for the oil temperature was 220 degrees.
Bernard
I have called Lycoming and explained my problem and the technician told me that if the oil temperature was in the range of 230 to 245 and over and the oil pressure was in the green arc from 50 to 85 psi the problem would certainly be at the gauge. Even if the gauge was looking to be OK with boiling water he told me that it had already happend that in the high range it could be defective. He told me also that when the oil temperature is going higher the oil pressure is going lower as much as 20 psi and in the yellow arc. He told me to use an infrared heat temperature gun and direct it on the oil pressure screen near the magnetos just after landing to check if the temperature would be about the same + or - 5 degrees by comparison with the gauge. I have read the article posted by Stewartb on avweb and I will double check everything they suggest to do. The technician also told me that the magic number for the oil temperature was 220 degrees.
Bernard
slow and low with good oil temps on hot days
I have a 1958 P.A. 18 with a 0-320 A2B. The guy I had purchased the plane from installed a second oil cooler that hangs down past the air ductwork. I don't like the looks of it but, it does keep the oil temps good, even on the hottest days down here in Houston Texas. I fly slow and low for long periods of time, so this set up works good for me. In cold weather I have to restrick the cooler with a tin wrap, and on the coldest days sometimes I place a small amont of tape on the front cooler also. I do this to get the temps up to take care of any moisture build up. It's a quessing game that I dont like to do. We have only a few really cold days down here, so I put up with the hassel and the looks of the cooler hanging down past the airbreather. Mark
I have a 1958 P.A. 18 with a 0-320 A2B. The guy I had purchased the plane from installed a second oil cooler that hangs down past the air ductwork. I don't like the looks of it but, it does keep the oil temps good, even on the hottest days down here in Houston Texas. I fly slow and low for long periods of time, so this set up works good for me. In cold weather I have to restrick the cooler with a tin wrap, and on the coldest days sometimes I place a small amont of tape on the front cooler also. I do this to get the temps up to take care of any moisture build up. It's a quessing game that I dont like to do. We have only a few really cold days down here, so I put up with the hassel and the looks of the cooler hanging down past the airbreather. Mark
Engine overheating
Maybe a help? Bought a new cub in late 70's to tow sailplanes. Ran fine from Lockhaven to Colorado Springs where Dave Johnson (now deceased) changed engine to new 0-360 and new prop. Tons of overheating problems. Dave pulled every hair out. Redid baffles and a bunch of other cooling tricks. Rabbit stayed in the hat. Lycoming said it was just tight and to use it. We tried but it really ran hot towing...imagine that! Final solution was in the engine. Calls to Lycoming got yawns because the hicks out in the boonies didn't understand engines. Finally friend and fellow pilot, not to mention attorney, called them and made our position clear. They sent a new engine and it ran cool. Very cool as a result of all the excellent baffle and other work done by Dave Johnson. Finally, a call to a friend 'inside' Lycoming revealed they had installed the wrong or improperly installed (we never found out) the camshaft. Just a thought, check the engine.
Maybe a help? Bought a new cub in late 70's to tow sailplanes. Ran fine from Lockhaven to Colorado Springs where Dave Johnson (now deceased) changed engine to new 0-360 and new prop. Tons of overheating problems. Dave pulled every hair out. Redid baffles and a bunch of other cooling tricks. Rabbit stayed in the hat. Lycoming said it was just tight and to use it. We tried but it really ran hot towing...imagine that! Final solution was in the engine. Calls to Lycoming got yawns because the hicks out in the boonies didn't understand engines. Finally friend and fellow pilot, not to mention attorney, called them and made our position clear. They sent a new engine and it ran cool. Very cool as a result of all the excellent baffle and other work done by Dave Johnson. Finally, a call to a friend 'inside' Lycoming revealed they had installed the wrong or improperly installed (we never found out) the camshaft. Just a thought, check the engine.
Fortysix12
Registered User
RanchAero Grand Vista, Brooksville
Re: Engine overheating
Makes good sense good information to know.
wdbrown said:
Makes good sense good information to know.
andres2249
Registered User
Caracas, Venezuela
How can the factory install a wrong cam? how can it even fit? incredible but true wow..........................................andres
belisle
Registered User
Quebec, CANADA
Found the problem
One of my friends bought a PA-12 project and when looking at it I noticed that his bottom cowling was different than mine. He had a curved lip on the aft part of it. So I made a wood form as a pattern and modify my cowling to the same as his. The temperature dropped for at least 20 degrees and fixed the high oil temperature problem. I think that is creating more vacuum to exit the hot air from the engine compartment. Thanks to all of you who gave me tips to fix my hot oil temp problem
Bernard
One of my friends bought a PA-12 project and when looking at it I noticed that his bottom cowling was different than mine. He had a curved lip on the aft part of it. So I made a wood form as a pattern and modify my cowling to the same as his. The temperature dropped for at least 20 degrees and fixed the high oil temperature problem. I think that is creating more vacuum to exit the hot air from the engine compartment. Thanks to all of you who gave me tips to fix my hot oil temp problem
Bernard
JB
FRIEND
Willow Creek, Alaska
I started having high oil temps the other day. Looking for some help. We checked the pressure screen it was clean. Oil analysis has been great. Borescoped cylinders all look great. Pulled the vernatherm and installed the oil bypass plunger and spring and it didn't seem to change. I can maintain 200degrees at 2250rpm but when I increase rpm the temp starts climbing. I don't have CHT or EGT only oil temp.
BC12D-4-85
SPONSOR
Fairbanks, AK.
JB, what does the oil pressure do when the oil temp increases? Is your mixture arm on the carb going to full rich when called for in the cockpit? Do you get a slight rpm rise in cruise when the mixture is slowly leaned at 2000' or lower (goes from rich to lean). What color is the exhaust pipe inside, and the spark plug tips? Are the plugs uniform in color among cylinders? What oil cooler do you have and were is it located? Is your engine baffling tight to the cowl and engine with no major gaps, same for oil cooler to nearby metal. Is your mag timing correct - not advanced? Is your oil breather tube pumping out more now than previously? Etc....
Gary
Gary
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