flyboy0681 Posted September 4, 2016 Report Share Posted September 4, 2016 The high CHT on #1 still continues to plague me even after the injector was cleaned, a new intake manifold gasket was replaced and baffle adjusted . I've been writing about this for the past year, yet #1 runs hotter than all of the others by about 30-35 degrees, averaging 400-405. Not wanting to see this on the display. I always land up opening the cowl flaps and enriching the mixture, resulting in my flying slower and using more gas. Two questions: 1. What else should I have looked at? 2. I'm getting tired or flying slow and rich, would anybody have any reservations running it at 400-410 as part of normal operations until it's solved? Quote Link to comment Share on other sites More sharing options...
carusoam Posted September 4, 2016 Report Share Posted September 4, 2016 Temps over 400°F may be normal for an M20C, not so normal for a fully instrumented engine with a non-doghouse cowl. Look at everything fresh... From heat generators to heat sinks... 1) does the EGT match the CHT? Does EGT 1 run higher than the others? 2) posting a photo and a graph can garner a lot of good feedback. 2.5) how is the GAMI spread for all cylinders? If all the EGTs are in line, how is the cooling working? 3) CHTs are highly dependent on the efficiency of airflow around the cylinder heads. 4) old stiff rubber and cracks or holes in the baffling can cause some pretty large issues. Bright lights in a dark hangar might be helpful... 4.5) What really stands out is the OAT that you may be seeing is probably quite high compared to other regions. Then there is the other logic, like is it a real issue of an instrument issue? 5) What CHT probe is actually measuring the errant number? 6) An IR thermometer can be really helpful for finding out if there are any real hot spots. 7) is there a piggyback TC being used or a ring under a spark plug? 8) see if swapping connections or trading in a new TC for the old one makes a difference... Final thoughts... 1) EGTs are all in line... 2) Instruments are all in line... 3) cowling is all fresh and intact... 4) GAMI spread is close to zero... 5) FF is a few °F LOP... 6) CHTs are all under redline. 7) OATs close to 100°F are going to cause some annoyance with CHTs. 8) What are the CHTs of other IO360s in the summer? 9) At what point do pilots accept flying slow/rich vs fast at the cost of a few cylinders? MSers have seen many odd wiring, TCs , and instrument set-ups over the years. Good engine and airframe grounding is also helpful. How does that PP logic sound? This is a collection of information I have gather from MS. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
flyboy0681 Posted September 4, 2016 Author Report Share Posted September 4, 2016 6 minutes ago, carusoam said: Temps over 400°F may be normal for an M20C, not so normal for a fully instrumented engine with a non-doghouse cowl. Look at everything fresh... From heat generators to heat sinks... 1) does the EGT match the CHT? Does EGT 1 run higher than the others? 2) posting a photo and a graph can garner a lot of good feedback. 2.5) how is the GAMI spread for all cylinders? If all the EGTs are in line, how is the cooling working? 3) CHTs are highly dependent on the efficiency of airflow around the cylinder heads. 4) old stiff rubber and cracks or holes in the baffling can cause some pretty large issues. Bright lights in a dark hangar might be helpful... 4.5) What really stands out is the OAT that you may be seeing is probably quite high compared to other regions. Then there is the other logic, like is it a real issue of an instrument issue? 5) What CHT probe is actually measuring the errant number? 6) An IR thermometer can be really helpful for finding out if there are any real hot spots. 7) is there a piggyback TC being used or a ring under a spark plug? 8) see if swapping connections or trading in a new TC for the old one makes a difference... MSers have seen many odd wiring, TCs , and instrument set-ups over the years. Good engine and airframe grounding is also helpful. How does that PP logic sound? Best regards, -a- All things to consider I guess. We thought it was the probe and installed a new one this week only to find that it agreed with the old one. As far as OAT is concerned, I'm seeing those temps while in cruise at 8,000 feet. The plane is in the Bahamas for the next week and I'll check the other stuff when she returns. Quote Link to comment Share on other sites More sharing options...
carusoam Posted September 4, 2016 Report Share Posted September 4, 2016 Post a beach picture! -a- Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted September 4, 2016 Report Share Posted September 4, 2016 Have you checked that your probes are correctly connected, i.e. Cylinder 1 probe is actually the probe on cylinder 1? Quote Link to comment Share on other sites More sharing options...
Hank Posted September 4, 2016 Report Share Posted September 4, 2016 24 minutes ago, flyboy0681 said: All things to consider I guess. We thought it was the probe and installed a new one this week only to find that it agreed with the old one. As far as OAT is concerned, I'm seeing those temps while in cruise at 8,000 feet. The plane is in the Bahamas for the next week and I'll check the other stuff when she returns. Today, coming across N. Ga. and SC at 7500, temps were in the high 60s to low 70s, well above ISA temps. I only have the one factory probe, but it was below the top of the green line in my C (mentioned above as notorious for running not). I was at about 70% power and 146 knots TAS (love that screen in the 430!). No pictures, I left my phone at home. Quote Link to comment Share on other sites More sharing options...
flyboy0681 Posted September 4, 2016 Author Report Share Posted September 4, 2016 9 hours ago, teejayevans said: Have you checked that your probes are correctly connected, i.e. Cylinder 1 probe is actually the probe on cylinder 1? Yup, new probe verified to be attached to #1. Quote Link to comment Share on other sites More sharing options...
mooneyflyfast Posted September 4, 2016 Report Share Posted September 4, 2016 (edited) Remove the baffle in front of the no. 1 cyl. (two machine screws).. Cut 3/4 inch off if it and reinstall.. Your problem is solved.. Had the same problem with my 81 J and after doing this my no. 1 went from hottest cyl. to second coolest.. Actually my mechananic made me a shorter one in literally 10 minutes at no charge.. This baffle is to keep no. 1 from running too cold-- makes no sense it it is too hot.. I don't know who originated this fix (not me) but it has been covered a lot on various threads and it seems to work. Edited September 4, 2016 by mooneyflyfast 1 Quote Link to comment Share on other sites More sharing options...
Oldguy Posted September 4, 2016 Report Share Posted September 4, 2016 I see where you have installed a new probe, but have you swapped connections to make sure it doesn't travel with the wire? Figure you probably have, but didn't see you mention it anywhere. 1 Quote Link to comment Share on other sites More sharing options...
Marauder Posted September 4, 2016 Report Share Posted September 4, 2016 If you have sufficient lead length, reconnect #3's probe to #1 and vice versa. Make sure you are not looking at an instrumentation or wiring issue. Sent from my iPad using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
flyboy0681 Posted September 5, 2016 Author Report Share Posted September 5, 2016 3 hours ago, Marauder said: If you have sufficient lead length, reconnect #3's probe to #1 and vice versa. Make sure you are not looking at an instrumentation or wiring issue. Sent from my iPad using Tapatalk Did that several steps ago. Nada. Quote Link to comment Share on other sites More sharing options...
Mooney in Oz Posted September 5, 2016 Report Share Posted September 5, 2016 19 hours ago, mooneyflyfast said: Remove the baffle in front of the no. 1 cyl. (two machine screws).. Cut 3/4 inch off if it and reinstall.. Your problem is solved.. Had the same problem with my 81 J and after doing this my no. 1 went from hottest cyl. to second coolest.. Actually my mechananic made me a shorter one in literally 10 minutes at no charge.. This baffle is to keep no. 1 from running too cold-- makes no sense it it is too hot.. I don't know who originated this fix (not me) but it has been covered a lot on various threads and it seems to work. +1 Worked for me too. Quote Link to comment Share on other sites More sharing options...
THill182 Posted September 5, 2016 Report Share Posted September 5, 2016 One other suggestion (follow-up on checklist posed earlier in this thread by carusoam ): I recently after an annual had unusual (for my engine) high CHT on Cylinder 3 (Ovation 310HP; IO550G). Also forced me to lean very aggressively and fly at lower power to keep CHT's below 380 on that cylinder (only; the others showed less than 350). Long story short, the injectors were swapped between cylinders at some point or so it seemed. changing #3 injector with #2 injector (which ran coolest) solved the problem. To diagnose this, do an abbreviated GAMI test. record CHT's and EGT's running ROP and LOP, at different fuel flows graduated by, e.g., .2 to .4 GPH. Then graph it. I saw that EGT on #3 was highest when running LOP, and also went over the top first when lean-finding from the lean side. Put another way, it was running much richer than the others. Anyway, swapping the injectors re-balanced the engine very nicely. Now all CHT's are within 6F. Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted September 5, 2016 Report Share Posted September 5, 2016 Remove the baffle in front of the no. 1 cyl. (two machine screws).. Cut 3/4 inch off if it and reinstall.. Your problem is solved.. Had the same problem with my 81 J and after doing this my no. 1 went from hottest cyl. to second coolest.. Actually my mechananic made me a shorter one in literally 10 minutes at no charge.. This baffle is to keep no. 1 from running too cold-- makes no sense it it is too hot.. I don't know who originated this fix (not me) but it has been covered a lot on various threads and it seems to work. Do you have a picture of what it looks like now? Quote Link to comment Share on other sites More sharing options...
mooneyflyfast Posted September 5, 2016 Report Share Posted September 5, 2016 7 hours ago, teejayevans said: Do you have a picture of what it looks like now? 7 hours ago, teejayevans said: Do you have a picture of what it looks like now? Sorry, no I don't.. I will try to remember to take one and post it the next time I go to the airport.. It looks exactly like the old one except it is 3/4 inch shorter. Quote Link to comment Share on other sites More sharing options...
211º Posted September 6, 2016 Report Share Posted September 6, 2016 My #3 is running hotter than the others on my E. About 40° hotter. I think my issue is the baffles. I'm posting only as a baseline for others that might also have one hot CHT. . Looks like gaps above is permitting the cooling air to move rearward, not downward (as I am assuming it should). Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
Guest Posted September 6, 2016 Report Share Posted September 6, 2016 Just now, 211º said: My #3 is running hotter than the others on my E. About 40° hotter. I think my issue is the baffles. I'm posting only as a baseline for others that might also have one hot CHT. . Looks like gaps above is permitting the cooling air to move rearward, not downward (as I am assuming it should). Sent from my iPad using Tapatalk Your baffle sealing tapes are doing absolutely nothing for cooling and it looks like your #3 CHT probe is a spark plug gasket type, it will read hotter than a bayonet type in the factory location. Clarence Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted September 6, 2016 Report Share Posted September 6, 2016 7 hours ago, teejayevans said: Do you have a picture of what it looks like now? 7 hours ago, teejayevans said: Do you have a picture of what it looks like now? Sorry, no I don't.. I will try to remember to take one and post it the next time I go to the airport.. It looks exactly like the old one except it is 3/4 inch shorter. I just want to know if mine has been modified, why would some require this mod and some don't? Quote Link to comment Share on other sites More sharing options...
cnoe Posted September 6, 2016 Report Share Posted September 6, 2016 16 hours ago, mooneyflyfast said: On 9/5/2016 at 8:35 AM, teejayevans said: 7 hours ago, teejayevans said: Do you have a picture of what it looks like now? On 9/5/2016 at 8:35 AM, teejayevans said: 7 hours ago, teejayevans said: Do you have a picture of what it looks like now? Sorry, no I don't.. I will try to remember to take one and post it the next time I go to the airport.. It looks exactly like the old one except it is 3/4 inch shorter. Look closely and you can see where it previously covered the cooling fins. Mine's only about 1/2" shorter than before. Still those baffle seals are very droopy. BeeGee's replacement kit worked great for me. Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
wpbarnar Posted September 6, 2016 Report Share Posted September 6, 2016 They make a smaller ring terminal probe that installs under the bayonet mount. I agree with "Eagle Eye" Clarence, the spark plug style read significantly higher. I swapped from the spark plug style to under the bayonet and saw a 60 degree drop in indication. Also looks like an ignition lead could be rubbing on a fuel injection line. Bill Quote Link to comment Share on other sites More sharing options...
Guest Posted September 6, 2016 Report Share Posted September 6, 2016 8 hours ago, wpbarnar said: They make a smaller ring terminal probe that installs under the bayonet mount. I agree with "Eagle Eye" Clarence, the spark plug style read significantly higher. I swapped from the spark plug style to under the bayonet and saw a 60 degree drop in indication. Also looks like an ignition lead could be rubbing on a fuel injection line. Bill The fuel injection line clamps don't meet the requirements of the current AD or SB, the push rod seal on cylinder 1 intake is leaking, and the fuel supply line from the servo to the flow divider has no fire sleeve and the elbow is not fully seated. Clarence Quote Link to comment Share on other sites More sharing options...
bradp Posted September 9, 2016 Report Share Posted September 9, 2016 Clarence will start tele-annuals next week. You send him pictures of your plane and he will tell you what needs to be fixed. 2 Quote Link to comment Share on other sites More sharing options...
Guest Posted September 9, 2016 Report Share Posted September 9, 2016 A new program I'm starting, send pictures of plane, log books and of course a cheque. $199.00 each with only limited spaces available, a 10% discount for the first 5 Mooney Space participants. Clarence Quote Link to comment Share on other sites More sharing options...
mooniac15u Posted September 9, 2016 Report Share Posted September 9, 2016 On 9/6/2016 at 6:37 PM, M20Doc said: The fuel injection line clamps don't meet the requirements of the current AD or SB, Can you provide more detail on this? Is it the orientation of the small and large clamp loops relative to each other that is incorrect in the photo? Does that place the lines too close to the engine? I'd like to make sure they are correct on my engine. Quote Link to comment Share on other sites More sharing options...
Guest Posted September 9, 2016 Report Share Posted September 9, 2016 Here is the SB referenced in the AD. Clamp part number, orientation and hardware are all called out in the SB. http://www.lycoming.com/Portals/0/techpublications/servicebulletins/SB 342G (07-16-2013)/Fuel Line and Support Clamp Inspection and Installation.pdf Clarence Quote Link to comment Share on other sites More sharing options...
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