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Thread: Fluctuating Oil Temp

  1. #1
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    Default Fluctuating Oil Temp

    My 363i oil temp rises into Caution and Warning levels even when oil pressure remains normal for the power setting.

    I'm going to replace the temp sensor.

    Does anyone know what part number for the oil temp sensor? There's no published parts manual for the 363i and the Cubcrafters parts person is still researching it for me.

    Thanks!

  2. #2
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    Default Re: Fluctuating Oil Temp

    Does it fluctuate up and then back down or just goes up and stays up? Which engine is it? (Who assembled?). The Superior ones (earlier serial numbers) needed to have half the oil cooler taped off. The 2 Lycomings I’ve had so far have not needed that.

    https://forum.cubcrafters.com/showth...ll=1#post23176

    1. Put a piece of 2" metal tape across half of your oil cooler. We use to do this to the CC340 engine to try and get oil temps up higher so it would burn off moisture in the oil but with cooler/freezing temps here in the CC363i, I also ran into a problem with it being untaped.

    The oil coolers are so efficient, that I guess they will actually get the oil "too cool". In my case, I was flying along around 28 degrees and the oil temps slowly went up to around 220 or 221 and then would quickly fall back to around 170 or so......then slowly increase again to the 220/221 and repeat. Back and forth.......

    What was happening was that the vernathem would allow the hot oil to go to the oil cooler when it heated up but the oil in the oil cooler was so cold that it essentially clogged up and wouldn't let the hot oil pass through quickly. Then it would evidently warm that oil up enough to get it moving out of the oil cooler and cycle the oil through there until the vernathem shut it off again......the oil in the cooler would gel up again ...... and on goes the cycle over and over.

    I covered half the cooler with the metal tape and the oil temps now stay PEGGED at 185. So I'll just leave the tape on year round unless I'm getting into the hot, southern summer temps and only if the temps go up. I've suggested to Mitch to add this to the EX3 SETUP FOLDER in Dropbox.





    Quote Originally Posted by robmillersdg View Post
    My 363i oil temp rises into Caution and Warning levels even when oil pressure remains normal for the power setting.

    I'm going to replace the temp sensor.

    Does anyone know what part number for the oil temp sensor? There's no published parts manual for the 363i and the Cubcrafters parts person is still researching it for me.

    Thanks!
    Dave Embry
    "You only live once.......but if you do it right.........once is enough."..

  3. #3
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    Default Re: Fluctuating Oil Temp

    Dave thank you!!!!

    Mine is an FX-3 with the 363i so factory assist. The builder is listed as Stoney Creek Aviation. I bought it second hand and have flown it for 100+ hours before this problem came up.

    Thanks!



    Quote Originally Posted by Daveembry View Post
    Does it fluctuate up and then back down or just goes up and stays up? Which engine is it? (Who assembled?). The Superior ones (earlier serial numbers) needed to have half the oil cooler taped off. The 2 Lycomings I’ve had so far have not needed that.

    https://forum.cubcrafters.com/showth...ll=1#post23176

    1. Put a piece of 2" metal tape across half of your oil cooler. We use to do this to the CC340 engine to try and get oil temps up higher so it would burn off moisture in the oil but with cooler/freezing temps here in the CC363i, I also ran into a problem with it being untaped.

    The oil coolers are so efficient, that I guess they will actually get the oil "too cool". In my case, I was flying along around 28 degrees and the oil temps slowly went up to around 220 or 221 and then would quickly fall back to around 170 or so......then slowly increase again to the 220/221 and repeat. Back and forth.......

    What was happening was that the vernathem would allow the hot oil to go to the oil cooler when it heated up but the oil in the oil cooler was so cold that it essentially clogged up and wouldn't let the hot oil pass through quickly. Then it would evidently warm that oil up enough to get it moving out of the oil cooler and cycle the oil through there until the vernathem shut it off again......the oil in the cooler would gel up again ...... and on goes the cycle over and over.

    I covered half the cooler with the metal tape and the oil temps now stay PEGGED at 185. So I'll just leave the tape on year round unless I'm getting into the hot, southern summer temps and only if the temps go up. I've suggested to Mitch to add this to the EX3 SETUP FOLDER in Dropbox.

  4. #4
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    Default Re: Fluctuating Oil Temp

    sorry, by “builder”, I meant “who is the engine builder.” These engines are assembled by either Superior or LYCOMING. I’m not sure where the serial numbers changed but just check your engine log book. The first engines were assembled by Superior but all the later and current ones by Lycoming.

    you didn’t mention if the temps cycles and go up and then back down etc or does it just go up and stay up? Is that in normal cruise, climb, descent etc?

    if the temps are cycling up and down, it could be what I explained with the vernatherm (oil thermostat) or oil cooler. This I found with the Superior 363i engines but not with the Lycomings for some reason.

    You can also email parts@cubcrafters.Com for the parts (oil temp transducer).

    Quote Originally Posted by robmillersdg View Post
    Dave thank you!!!!

    Mine is an FX-3 with the 363i so factory assist. The builder is listed as Stoney Creek Aviation. I bought it second hand and have flown it for 100+ hours before this problem came up.

    Thanks!
    Dave Embry
    "You only live once.......but if you do it right.........once is enough."..

  5. #5
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    Default Re: Fluctuating Oil Temp

    Thanks Dave!

    The oil temp goes up then stays above caution range, fluctuating in the yellow arc by about +/- 10 degrees. Oil pressure seems normal. This was the first engine start after an oil change by an A&P.

    This started when the oil temp spiked to 280 during takeoff. I landed safely but was never able to replicate the reading just taxiing around on hot days until after the oil change.





    Quote Originally Posted by Daveembry View Post
    sorry, by “builder”, I meant “who is the engine builder.” These engines are assembled by either Superior or LYCOMING. I’m not sure where the serial numbers changed but just check your engine log book. The first engines were assembled by Superior but all the later and current ones by Lycoming.

    you didn’t mention if the temps cycles and go up and then back down etc or does it just go up and stay up? Is that in normal cruise, climb, descent etc?

    if the temps are cycling up and down, it could be what I explained with the vernatherm (oil thermostat) or oil cooler. This I found with the Superior 363i engines but not with the Lycomings for some reason.

    You can also email parts@cubcrafters.Com for the parts (oil temp transducer).

  6. #6
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    Default Re: Fluctuating Oil Temp

    Well, I’m not an A&P so all I can pitch in with is what my experience have been, and I haven’t had one just run a little high. Maybe some of the engine guys could jump in.

    just off the cuff guess I might question a couple of things. Seems strange this happened right after an oil change.

    1. Same oil viscosity or a change?
    2. Did you run it long enough to see if the vernatherm would open and let oil run through the oil cooler or did you just see it high after takeoff and then land?
    3. By chance “is” your oil cooler maybe taped off now? Look up into the top, center area through the front with a flashlight and you should be able to see if it is. Usually just a thin, metal tape over part of the oil cooler on the front side. If so, just pull it off.
    4. Any rise in the CHT’s?
    5. The oil temp transducer of course could be bad but…..short of being a more serious engine problem,…..(which I would doubt) the vernatherm or the oil cooler would be my first guess. There just has to be some coincidence of an oil change and then this??? The transducer is wired of course. A bad connection might make it fluctuate…..but probably pretty wildly.

    sorry. That’s my best guess. Please keep us posted what you end up figuring out.

    Quote Originally Posted by robmillersdg View Post
    Thanks Dave!

    The oil temp goes up then stays above caution range, fluctuating in the yellow arc by about +/- 10 degrees. Oil pressure seems normal. This was the first engine start after an oil change by an A&P.

    This started when the oil temp spiked to 280 during takeoff. I landed safely but was never able to replicate the reading just taxiing around on hot days until after the oil change.

    Dave Embry
    "You only live once.......but if you do it right.........once is enough."..

  7. #7
    Senior Member Andy's Avatar
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    Default Re: Fluctuating Oil Temp

    Quote Originally Posted by robmillersdg View Post
    My 363i oil temp rises into Caution and Warning levels even when oil pressure remains normal for the power setting.

    I'm going to replace the temp sensor.

    Does anyone know what part number for the oil temp sensor? There's no published parts manual for the 363i and the Cubcrafters parts person is still researching it for me.

    Thanks!

    Look for electrical connection problems between the sensor and the GEA 24. In particular look at your data log for abnormal sensor readings during engine start. The starter current will bias the readings of any sensor with a bad ground. I would estimate the probability of a sensor failure as close to zero and a wiring issue at 90%+

    The temperature sensor is close to the oil filter so the fact that the problem started just after a filter change is probably not a coincidence.

  8. #8
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    Default Re: Fluctuating Oil Temp

    THANKS FOR THE ADVICE!

    Once again we proved Occam's Razor. The simplest explanation was indeed the correct one.


    The connector between the panel and the oil temp sensor was not very tight. We tightened it and locked it down with some zip ties and SHAZAM! Problem solved.

    Thank you again Dave and Andy for your generosity of time and advice!




    Quote Originally Posted by Andy View Post
    Look for electrical connection problems between the sensor and the GEA 24. In particular look at your data log for abnormal sensor readings during engine start. The starter current will bias the readings of any sensor with a bad ground. I would estimate the probability of a sensor failure as close to zero and a wiring issue at 90%+

    The temperature sensor is close to the oil filter so the fact that the problem started just after a filter change is probably not a coincidence.

  9. #9
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    Default Re: Fluctuating Oil Temp

    great news. Thanks for letting us know!

    Quote Originally Posted by robmillersdg View Post
    THANKS FOR THE ADVICE!

    Once again we proved Occam's Razor. The simplest explanation was indeed the correct one.


    The connector between the panel and the oil temp sensor was not very tight. We tightened it and locked it down with some zip ties and SHAZAM! Problem solved.

    Thank you again Dave and Andy for your generosity of time and advice!
    Dave Embry
    "You only live once.......but if you do it right.........once is enough."..

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