Jab 3300 EGT

[paulgy80]

I have a Jab 3300 with a D10 on, I have rapid fluctuation on the oil temp and have done since new. I spoke to one of your guys at Friedrichshafen, the installer and on this forum all bar my installer says earth?? The earths have been checked and the problem remains !!! it is as if the D10 needs some damping in the system.

Now for some reason after 30 hours of trouble free EGT operation I have one cylinder that is fine during warmup but in flight whilst all the others hover about 730c this one fluctuates wildly between 620 and 850.

Would appreciate your input

On the positive side the tacho works...........at the moment

Paul

 

[dynonsupport]

Paul, oil temp issues are basically always ground issues. Unfortunately, it's complex, and not just as simple as checking grounds visually. The way you can prove this to yourself is to turn off the alternator. You'll see that the oil temp is suddenly stable. That's because the current from the alternator no longer goes across the cable from your engine to your airframe and battery. This means your connections are not electrically robust, either due to corrosion, painted connection points, or just a cable that is too small.

Here's another post on the topic:
http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1238221132/1#1

As for the EGT probe, pull it out and see if it's still physically OK. You can also cross wiring and make sure it stays with the physical probe, not the channel on the EMS.