Al Downs Posted May 31, 2014 Report Share Posted May 31, 2014 Went for a ride this morning and on climb out started getting CHT alarms on the right side. Highest temp I saw was 246. Only went around once and came back to investigate. I see nothing wrong but went around once more with the same results. Any ideas? Link to comment Share on other sites More sharing options...
Tom Baker Posted May 31, 2014 Report Share Posted May 31, 2014 Increased resistance will cause the temp to read higher than it really is. If you have an inferred thermometer you can check the temp and compare to the Dynon, just shoot the temp at the probe. One other thing I have seen is a stuck thermostat cause the temps to go high. If this is the problem your radiator will feel cooler that it should for the high temps. Link to comment Share on other sites More sharing options...
Anticept Posted May 31, 2014 Report Share Posted May 31, 2014 Stuck thermostat will affect the oil temp alarm well before you see any CHT problems (experienced first hand last week). If the CHT alarm is going off, but the engine isn't feeling rough and EGTs are still normal, it is likely a probe problem. I could see a clogged coolant exit port causing a high CHT, but that should affect EGT too. Link to comment Share on other sites More sharing options...
Tom Baker Posted May 31, 2014 Report Share Posted May 31, 2014 Stuck thermostat will affect the oil temp alarm well before you see any CHT problems (experienced first hand last week). If the CHT alarm is going off, but the engine isn't feeling rough and EGTs are still normal, it is likely a probe problem. I could see a clogged coolant exit port causing a high CHT, but that should affect EGT too. Well I would guess it depends on which thermostat is stuck, there are 2 on the CTLS. I picked up a airplane to work on with this problem. I had a CHT alarm before the oil was even up to 122° to do the run up. Radiator was cool and the cylinders were hot. Tapped on the thermostat, heard it click and the heat transfer to the radiator started. Link to comment Share on other sites More sharing options...
Anticept Posted May 31, 2014 Report Share Posted May 31, 2014 I didn't put a bet on it being aldown's coolant thermostat because it only tripped one alarm, I would figure that would have tripped both. Link to comment Share on other sites More sharing options...
Tom Baker Posted May 31, 2014 Report Share Posted May 31, 2014 I didn't put a bet on it being aldown's coolant thermostat because it only tripped one alarm, I would figure that would have tripped both. I wasn't talking about Al's airplane. It was a different CT that I saw the problem. The coolant thermostat being stuck will not cause other problems, unless you let it go to far. the right side will normally alarm first, but the left side temp will be close behind. If there is a big spread between the left and right, it is likely not the thermostat. Link to comment Share on other sites More sharing options...
Anticept Posted May 31, 2014 Report Share Posted May 31, 2014 Got ya Link to comment Share on other sites More sharing options...
Al Downs Posted June 3, 2014 Author Report Share Posted June 3, 2014 Today I swapped the CHT sensors from side to side. I was still able to duplicate the problem on the ground. I removed the cowls and checked the temp at the probes. Right side was at least 10% hotter but cooled to safe levels by the time I got the cowls off. Antifreeze level is fine and the radiator looks clean. Tomorrow I will clean the outside of the radiator to make sure there is no build up of anything there. Any other ideas? Link to comment Share on other sites More sharing options...
Roger Lee Posted June 3, 2014 Report Share Posted June 3, 2014 loose spade connectors will cause this. They should be firm on the probes and then check the wires down stream. Link to comment Share on other sites More sharing options...
Al Downs Posted June 12, 2014 Author Report Share Posted June 12, 2014 Got all of my problems solved. I have no idea why things started to happen all at once but one EGT probe and Fuel pressure sensor turned out to be bad. Other readings began to get flakey after my original post and we found 4 out of the 5 grounds loose. I mean really loose. I don't understand this as they were all tightened a year ago. Any everything looks good now. Thanks for your help. Link to comment Share on other sites More sharing options...
Anticept Posted June 13, 2014 Report Share Posted June 13, 2014 Got all of my problems solved. I have no idea why things started to happen all at once but one EGT probe and Fuel pressure sensor turned out to be bad. Other readings began to get flakey after my original post and we found 4 out of the 5 grounds loose. I mean really loose. I don't understand this as they were all tightened a year ago. Any everything looks good now. Thanks for your help. Put a second nut, or conductive threadlock compound on the terminals if you are referring to terminal studs. Link to comment Share on other sites More sharing options...
Doug G. Posted June 13, 2014 Report Share Posted June 13, 2014 OK, where do I find conducive thread locker? What brand? Link to comment Share on other sites More sharing options...
Anticept Posted June 13, 2014 Report Share Posted June 13, 2014 http://tds.loctite.com/tds5/docs/3888-EN.PDF (USE A SMALL DAB AFTER TORQUING, where the nut meets the threads. This stuff is meant to be a stand in for solder!) Or, as I said, use a second nut. Or use a lock washer between the nut and another washer on the ring terminal side so you don't damage them). Or, just use non-wicking loctite and put a drop on after it has been torqued down, and check resistance after curing. Lots of little ways to do it Link to comment Share on other sites More sharing options...
Roger Lee Posted June 13, 2014 Report Share Posted June 13, 2014 If you are using Nylok nuts which probably all of us are then Loctite or a second nut shouldn't be needed. The reason most of our Nylok nuts seem to get loose isn't because they back off it is from settling. As plastics or wires sit under a crushing pressure from tightening they can and do settle. This happens after 1 and sometimes two tightening's, but usually stops after that second tightening. Most just fail to apply enough torque on them up front. I make sure every ground nut is really tight at the 25 hr. check when new and at the 100 hr. check. They almost never come loose again. Link to comment Share on other sites More sharing options...
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