New to the list, bought a kitfox with a 912. Doing an inspection prior to calling an A&P to sign off the condition inspection.Now I am new to the 912 engine so I am trying to go over things as best as I can, tracing wires and hoses etc to get a beter understanding of where they go and what they do. Now I see the oil pressure and oil temp sending units on the firewall at the end oof what appears to be a hose from the lower right side of the gearbox. (see the photo the sending units are labeled and the purple line is where the hose is routed). Now I can see how the pressure sending unit would work there - but I dont see how the temperature sending unit could be accurate at the END of a hose without oil FLOWING through it. Any thoughts or is this location common on kitfoxes ?
I agree that it doesn't seem right to have the temp sensor absent any oil flow. I know that many recommend mounting the pressure sensor off the engine for protection against vibration. It looks like, from your picture, you have the same sensor I put 900 hours on without failure. The temp sensor, on the other hand was a regular at not showing up for work - replaced four times in that period.
The typical rubber oil lines on the engine are the blow by line that moves oil from the crank case to the remote tank and the pick up line that sucks oil from the tank then to the pump - neither pressurized. I just don't know how comfortable I would be running a 70 psi. line the length of the engine compartment. I am wondering if there is a real problem with sender failure on the engine or if it is just one of those things we do because someone says we should.
OK so the oil temp sending unit is in the wrong place. I am figuring on removing it from the fitting it is in - putting a plug in the fitting. Getting a tee fitting and cutting the hose right next to it that goes to the oil cooler and installing it there. Sound like a plan?
Can anyone tell me what size threads these things have so I can
1 buy a plug for where it is now and
2 get a tee for the hose (hose barbs on the ends and threaded fitting in the center) - if you know what kind I need and where I can get one please let me know
I would rather have the parts to put it back together before I take it apart
Thanks
The Oil Temp Sensor is supposed to be screwed into the front of the casting at the base of the oil filter (where oil is flowing)- opposite side of the engine from where your oil pressure hose screws onto the right side of the engine.
Depends on your sensor - but a lot of the gauges work off a really small thermister which looks like a bolt with wires coming off the top of its head.
Had another thought - if you have a Hobbs meter - some of them use a second pressure sensor in series with the hobbs to cut the hobbs off when the engine stops so you don't run up hours with the engine off in case someone leaves the master switch on - see a lot of these installations on rental airplanes (for obvious reasons) .....what you think is a temp sensor could potentially be one of these pressure switches.
Tomorrow when I get a chance I am going to gather a bit more infformation - reading the manual I see where the sensor is on the front of the engine and there is nothing wired to that. The temp gauge is part of a quad gauge and the wires are all white and hard to trace in the bundles.
Had not thought about a pressure switch for the hobbs. Thanks alll for the help. I will let you know what I find.
Well Dave you were exactly right it is a pressure switch for the hobbs and there is a red light on the panel that figures in there too. The light was not labeled, I feel like such a dufus. I did find the oil temp sending unit - looks like it is in the oil drain plug on the bottom of the motor. I also found (what looks like) temp sending units on the right rear and left front cylinder heads that are not hooked to anything. The wires just end in a wire bundle behind the panel - no gauge to hook them to.
Thank for the help . . Joe
Joe - The senders in the heads are for coolant temp / cylinder head temp (same reading). On my plane one goes to the coolant temp gauge and the other goes to the cylinder head temp gauge.
Av8r3400 Kitfox Model IV
The Mangy Fox
912UL 105hp Zipper YouTube Videos
Hello All
This is the closest thread I find concerning oil temp senders. Recently I notice my oil temp gauge indicator (Wetach Quad type) jumping around quite a bit. Is this what happens when the sender starts to fail? Connectors all seem tight. Any comments appreciated.
Thanks
Don Vixen 912UL.
Don't know if this will help; but, I also have the Westach/quad gauge. About a year ago, the oil temp sensor failed....slowly.
What happened is it would drop to zero and then go back to working. This behavior of the oil temp indicator was intermittent. Once in a while at first - then more often and it finally died and stayed at zero.
If I recall - there is a procedure to check the gauge and the sender with a multimeter, described in the westach documents that came with the senders/gauge, to determine which is at fault.
912 oil temp sending unit location
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