Flashing Lane B light after initial start and warm up - Anyone else seen this ?

Click for a video demonstration of the issue

Start up, wait for >50 C (or even wait for 63C) oil temp, whilst keeping rpm < 2500. Then as soon as the RPM is advanced to 3400, Lane B starts flashing. The G3X FADEC message reports,

"Lane B Status - Advisory"

"Oil Temperature  x Sensor Fault"

However the oil temp is fine and the problem goes away after Lane B is recycled. Problem does not recur during taxi or flight. Only comes back after the engine cools and is restarted.

I did a BUDS download, as a result, Rotax suggest it's because there's is too wide a differential between water coolant temperature (>100C) and Oil (>52 C) at the point when the RPM is advanced above 2500. The plane had no engine probelms in its first 100 hrs. It only recently started happening, but now every start up. So what's changed.

Has anyone got a flashing Lane B on start up. Any ideas how to solve this ?

Actions so far.

Looking at the G3X engine logs over the first years flying (120 hrs), it looks like the coolant temperature is 10 to 20C higher than at the beginning of the season.

The resistance of the coolant sensor has been checked against indicated temperature and the ohm values are consistent with the values in the heavy maintenance manual.

All auto style connectors on the ignition coils have been crimped tight. Extra P clips added. Wiring to oil temp sensor checked for chafing and cable tied firmly.  

Aircraft is a new build Sling TSI 915iS standard install, no thermostats in oil or coolant lines.

  • Re: Flashing Lane B after initial start and warm up

    by » 5 months ago

    Hi Peter

    Perhaps start with a check of the sensor values as shown in the Heavy Maintenance Manual.


  • Re: Flashing Lane B after initial start and warm up

    by » 5 months ago

    sorry, did not attach it for you...

    38237_2_oil temp sensor check.jpg (You do not have access to download this file.)

  • Re: Flashing Lane B after initial start and warm up

    by » 5 months ago

    Not sure if you've got it solved already, but here's my 2 cents-

    What battery are you using? The only time I've gotten flashing lane lights on startup was with lead-acid batteries that don't have enough CCA. They usually work fine for about 50-100 hours before it starts doing it. That's usually right at startup though, not after it's running for a while. Lipo batteries like Earth-X solve this version of the problem.

    Your oil temp looks right for idling a few minutes after startup, but the coolant is wildly high... you can pretty much idle on a hot day for an hour without moving, and it still probably wouldn't get that high on a Sling. Usually we have to do tricks to keep the coolant temp UP to run the heater, but never have to do anything to keep it down. Have you always had this high of coolant temps?

    If your oil temp sensor ohms out correctly, I'd investigate the coolant system. I see you don't have a thermostat, but if you have tape on your radiator, remove it. If no tape is installed, check the system for kinked lines, check the coolant temp sensors, make sure within spec. Last, maybe the water pump is damaged and not moving coolant through the system well enough? 



  • Re: Flashing Lane B after initial start and warm up

    by » 5 months ago

    Thanks Evan, some useful ideas to try there.  It's a lead acid battery. No tape on coolant radiator.

    I will go back through the g3x data logs and see what coolant temps I got last spring. But I think it's always been around 100C . Could have crept up a bit as 114C soon after start up is a bit high. In flight it's lower and quite stable. Thanks for your comments. 

  • Re: Flashing Lane B after initial start and warm up

    by » 5 months ago

    100c is too high also unless it's very hot outside. You've got something wrong with your coolant system, 100% for sure.

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