pkofman Posted December 26, 2019 Report Posted December 26, 2019 All I started to hear a really high pitch noise and checked the edm 700. This is what I see on the monitor. # 4 is either not firing or something else. Engine is not really running rough and oil pressure seems perfect Anyone understand this. Sorry do not know why they load incorrectly why uploading Peter Quote
pkofman Posted December 26, 2019 Author Report Posted December 26, 2019 (edited) I don’t think so where are the other readings. I also heard a different very high pitch noise note differential 230 degrees Edited December 26, 2019 by pkofman Quote
MIm20c Posted December 26, 2019 Report Posted December 26, 2019 (edited) Low voltage alarm? Should be 28ish with the engine running. What do you mean by other readings? Edited December 26, 2019 by MIm20c Quote
pkofman Posted December 26, 2019 Author Report Posted December 26, 2019 I did not have a low-voltage alarm if you look at the CHT and Egt neither are showing correctly initially CYLINDER four is blank. The plane just came off annual only about a week ago I don’t understand what’s going on with this is not normal for this plane so I won’t fly it until iunderstand it Quote
Niko182 Posted December 26, 2019 Report Posted December 26, 2019 3 minutes ago, pkofman said: I did not have a low-voltage alarm if you look at the CHT and Egt neither are showing correctly initially CYLINDER four is blank. The plane just came off annual only about a week ago I don’t understand what’s going on with this is not normal for this plane so I won’t fly it until iunderstand it How much power is there, low voltage and low egt makes me think low power. At idle my vopts are low and some egts dont even get above 1000 degrees so it doesnt show up on a bar. Did you do a runnup? Quote
pkofman Posted December 26, 2019 Author Report Posted December 26, 2019 This was different because I had no bar on number four and I heard kind of a high pitch sound it was different my voltage was not particularly low or lower than normal at low idle I’ve never seen that differential between the cylinders before Quote
Oldguy Posted December 26, 2019 Report Posted December 26, 2019 Did the squeal (high pitched sound) vary with RPM? Do you download your JPI data regularly or do you have the download capability? If you have the capability, load your data up to Savvyanalysis.com. Was there anything specific done during your annual out of the ordinary? Just trying to get some more information to narrow down where to begin looking. Quote
LANCECASPER Posted December 26, 2019 Report Posted December 26, 2019 Make sure the plug on the back of the JPI is seated in tightly. Quote
pkofman Posted December 26, 2019 Author Report Posted December 26, 2019 18 minutes ago, Oldguy said: Did the squeal (high pitched sound) vary with RPM? Do you download your JPI data regularly or do you have the download capability? If you have the capability, load your data up to Savvyanalysis.com. Was there anything specific done during your annual out of the ordinary? Just trying to get some more information to narrow down where to begin looking. See above very high pitch noise did not really change with rpm it was barely detectable unless you fly the plane allot I noticed it I can’t download data I don’t think anything special was done during the annual and all compressions were normal But @mooneydoc might have an idea 1 Quote
Rick Junkin Posted December 26, 2019 Report Posted December 26, 2019 A couple of thoughts - 1. Could the squeal be coming from one of the alternator belts? Is it that kind of squeal or something else? 2. Just came out of annual - are the plugs torqued properly? Wouldn't be the first time spark plugs were only hand tight. It happens. 2. Are your pictures of the EDM at idle power? They appear to be. That could contribute to the 23.7V indication especially if a belt(s) is slipping. 3. Troubleshooting step for the EDM - select "Normalize" mode (LF depressed for 2 seconds) and confirm that #4 has a level indication with the other 5 cylinders for EGT and CHT. At least you'll get an idea of the status of the #4 sensors. If #4 data looks different than the rest when normalized I'd look at the sensor continuity and the secureness of the harness plug at the EDM as Lance suggested. 4. Do you see better performance from #4 and voltage closer to 28V at a higher power setting? Niko asked about doing a run-up - I have the same question. See #2 first though. 5. If everything else checks ok, a leaned higher power mag check, as lean as you can get it, may also give you an indication of an ignition system problem. Just watch the temps so as not to exceed limits. From the mind of a man who looks for the simple thing first. Those are the things I would check. Cheers, Rick 2 Quote
pkofman Posted December 26, 2019 Author Report Posted December 26, 2019 43 minutes ago, Junkman said: A couple of thoughts - 1. Could the squeal be coming from one of the alternator belts? Is it that kind of squeal or something else? no it was a very very frequency not like a car fan belt squeal 2. Just came out of annual - are the plugs torqued properly? Wouldn't be the first time spark plugs were only hand tight. It happens. dont know @mooneydoc might have better idea 2. Are your pictures of the EDM at idle power? They appear to be. That could contribute to the 23.7V indication especially if a belt(s) is slipping. these taken at idle just after a run up 3. Troubleshooting step for the EDM - select "Normalize" mode (LF depressed for 2 seconds) and confirm that #4 has a level indication with the other 5 cylinders for EGT and CHT. At least you'll get an idea of the status of the #4 sensors. If #4 data looks different than the rest when normalized I'd look at the sensor continuity and the secureness of the harness plug at the EDM as Lance suggested. Ill try this 4. Do you see better performance from #4 and voltage closer to 28V at a higher power setting? Niko asked about doing a run-up - I have the same question. See #2 first though. forgot to check the voltage during the run up but everything else checked out 5. If everything else checks ok, a leaned higher power mag check, as lean as you can get it, may also give you an indication of an ignition system problem. Just watch the temps so as not to exceed limits. I just had the mags done... maybe that is relevant or not.. Mag check on run up was within Poh limits or better From the mind of a man who looks for the simple thing first. Those are the things I would check. Cheers, Rick Quote
Rick Junkin Posted December 26, 2019 Report Posted December 26, 2019 9 minutes ago, pkofman said: no it was a very very frequency not like a car fan belt squeal Very high frequency squeal with low EGT and CHT at idle - possible induction leak on #4? I'm not sure how that would squeal though, now that I think about it, but it might? You've already got one of the finest on it if @mooneydoc is engaged so I'll stop guessing now... Good luck, please let us know what you find. Cheers, Rick Quote
carusoam Posted December 27, 2019 Report Posted December 27, 2019 Wait a minute.... what doc is that? Did you mean @M20Doc? Aka Clarence. Best regards, -a- Quote
pkofman Posted December 27, 2019 Author Report Posted December 27, 2019 Just now, carusoam said: Wait a minute.... what doc is that? Did you mean @M20Doc? Aka Clarence. Best regards, -a- damn yes I made a mistake...aka clarence.. I screwed that up. Clarence aka Tri City.. @M20Doc 1 Quote
carusoam Posted December 27, 2019 Report Posted December 27, 2019 High pitched noise and a missing EGT sensor... They may be related... In an odd way... Do you have a CO monitor on board? I think if my EGT sensor got loose, it may start giving some bad data.... and my CO meter may start working in overdrive.... Can you swap two EGT sensors temporarily to see if the problem follows the sensor...? PP thoughts only, not a mechanic... Best regards, -a- Quote
carusoam Posted December 27, 2019 Report Posted December 27, 2019 What is belt driven on the affected Bravo? Only the spare alternator? Only the primary alternator? Does it sound like a belt squeal? Slipping belts have a capability to squeal... Makes you want to take the cowl off and see what may have come loose... PP guesses only, not any PP logic involved... Best regards, -a- Quote
pkofman Posted December 27, 2019 Author Report Posted December 27, 2019 I don’t know if the second alternator is belt driven or not. Someone here will know. it was not a squeal or a sound like a lose fan best in a car. Very very high frequency sort of sound Quote
carusoam Posted December 27, 2019 Report Posted December 27, 2019 Last piece of logic I can get out of the pictures... One pic shows the CHT #4 with its corresponding EGT... (a missing bar in the graph) EGT#4 is the one asking for a check-up... (the missing CHT bar doesn’t show when the graph has gone missing) does the EGT wire go anywhere near a moving part? Best regards, -a- Quote
LANCECASPER Posted December 27, 2019 Report Posted December 27, 2019 18 minutes ago, pkofman said: I don’t know if the second alternator is belt driven or not. Someone here will know. it was not a squeal or a sound like a lose fan best in a car. Very very high frequency sort of sound Both alternators on the M20M are in front and are belt driven. 1 Quote
Rick Junkin Posted December 29, 2019 Report Posted December 29, 2019 From the EDM manual. Possibly one of the two bottom cases? Cheers, Rick 20191229_Page 22.pdf 1 Quote
carusoam Posted December 29, 2019 Report Posted December 29, 2019 Any updates, PK? 1) Seems like the pics of data are from a low MP setting... 2) the low MP is probably causing a few secondary issues like the low V.... 3) Lots of interest in the high frequency sound.... 4) Lots to expect with the low EGT on one cylinder... Things that alter the compression like a leaky valve.... Leaky spark plug... CO and fire hazard... fuel not burning in the cylinder, may show up in elevated TIT readings... Of course... a loose EGT sensor will cause some low readings and possible odd sounds... 5) Nothing obviously connecting the squeal to the low EGT... unless the exhaust valve isn’t getting oil, and it’s Screamin’ for some... 6) If you want to get data downloaded out of the JPI... jpi sells the various wires and plugs and converter to make it happen... PP thoughts only... Best regards, -a- Quote
pkofman Posted December 29, 2019 Author Report Posted December 29, 2019 (edited) 1 hour ago, carusoam said: see below. thank you for checking in. Any updates, PK? No updates as I left town and cancelled my trip via the mooney so im not back until tomorrow but the shops are all pretty much closed until the 6th but we have tons of bad weather and ice in the forecast for the coming days so the plane is going to sit in the hangar and im not flying it until I know that it is safe to fly.. I reviewed the manual sent earlier to me and it says it might be a light or compression but the compressions were all in the high 70's a week ago. Btw I had the magnetos o/h on this annual , I dont know if that could be the issue 1) Seems like the pics of data are from a low MP setting. PK Yes except for one that I took right after a run up.. 2) the low MP is probably causing a few secondary issues like the low V.... PK most likely ( they are going to check the alt's) 3) Lots of interest in the high frequency sound.... PK Me too. it was new and not mechanical in nature 4) Lots to expect with the low EGT on one cylinder... this is all very strange in that the annual did not show and of the issues below. Ive only flown 1 hour since annual @M20Doc may know better Quote Things that alter the compression like a leaky valve.... Leaky spark plug... CO and fire hazard... fuel not burning in the cylinder, may show up in elevated TIT readings... Of course... a loose EGT sensor will cause some low readings and possible odd sounds... 5) Nothing obviously connecting the squeal to the low EGT... unless the exhaust valve isn’t getting oil, and it’s Screamin’ for some... 6) If you want to get data downloaded out of the JPI... jpi sells the various wires and plugs and converter to make it happen... PK I dont get data from the jpi.. PP thoughts only... PK Happy New Year to all and I will report back once I have some idea as to what is going on,.could not have happened at a worse time of year!!!!!! Best regards, Quote -a- Edited December 30, 2019 by pkofman 1 Quote
pkofman Posted January 4, 2020 Author Report Posted January 4, 2020 So here is a little update. Firstly its the holidays ( everyone is back Monday ) so im hoping to get the plane to the shop to get the edm looked at , however Ive flown the plane a few times because the gauge is not required equipment ( a advisory only) and although I have an odd indication on #4 ( reading a delta of 350) below all of the other cylinders the plane is running and "runs-up" perfectly. everything seems normal. I also spoke to JPI. They said , get it checked ( probably probes or a wire ) and if that is not the case it is a faulty screen . I dont know much but I do know that if one cylinder was offline it would not sound good at all. Further I am developing about 36.8 in of MP at 0C and that is consistent with prior indications.So ill fly the plane to the shop and ill let everyone know what the tech guys find out. Then there was the odd issue of the high pitch noise. It turn out that it was the T&B indictor gyro. Perhaps it was not enjoying the canadian cold weather. Ill have to watch it but I was able to isolate it and pull the breaker and I could start and stop this really super high pitch annoyance. It was just strange that it started at the same time as the edm700 went sideways. 1 Quote
carusoam Posted January 5, 2020 Report Posted January 5, 2020 Great update PK! Do you have a BU AI? Or is the TC the only back-up for the main AI? A Dynon D3(?) portable would be good until things get back to normal... PP thoughts only, not a mechanic or CFI... Best regards, -a- Quote
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