KyleKJ90

Keep in mind the measured fuel flow check was done with the nozzles disconnected. I was merely checking the flow divider and there's a small chance that the hangar floor wasn't perfectly even when I did this. :-/ I've borescoped the entire #2 intake tube through the injector threaded hole down to the area in the pan where the other intake tubes are. Nothing noted other than a puddle of oil down at one spot in the intake tube. I haven't borescoped the exhaust other than the exhaust valve and seat which I accessed through a spark plug hole.

I must be going to bed but here's exactly what I sent to Lycoming yesterday. Sorry in advance for the lengthy comment but it's everything and anything in order that we've done. Hope this helps. Hello Ryan, I apologize for the delayed response. As we discussed the other day we're still getting a higher than normal EGT indication on our #2 cylinder. Looking over my borescope videos of the #2 cylinder I realized that I have more footage of the valves than the actual cylinder wall so they won't be of much use if I sent them. I'd like to enclose the engine monitor data for the particular flight where this issue first happened. It becomes very apparent that something has happened to the #2 cylinder around the 2 hour 21 minute mark. https://www.savvyanalysis.com/flight/909290/0b7cfa44-4d8a-4fc1-8b1d-e351520276c0 The following flight after this one can be seen here and confirms the high EGT. https://www.savvyanalysis.com/flight/909291/4081b956-abf9-4d21-8494-3e2b15460c1f I can confirm that the engine monitor (JPI EDM 700) is working correctly as I have swapped both the probes and their respective channels of cylinders #2 and #4. The JPI confirms a hot EGT on the #2 cylinder and there doesn't appear to be any issue with the engine monitor. Just to confirm what all has been checked up to this point and in order of which they were done, I've listed all the items and their result below. 1. Cleaned fuel nozzles - No change noted 2. Swapped EGT probe from #2 cylinder to the #4 cylinder - No change noted 3. Attached #2 EGT probe wires coming from the JPI to the #4 cylinder and vice versa (The JPI showed the #2 EGT as cylinder #4 on the gauge. This was done to check gauge/channel for a fault.) - The result was a high EGT on the #4 indication on JPI. 4. Performed in flight induction leak check and in flight mag check. - No defects noted. 5. Installed a NEW EGT probe to #2 cylinder per other owner's request - No change noted 6. Cleaned fuel nozzles again. Cleaned, gapped and rotated spark plugs. #2 cylinder plugs looked oily compared to all the rest. - No change noted 7. Swapped fuel nozzles between #2 and #4 cylinders. Flow checked fuel coming from manifold tubes into containers. Fuel flow appeared to be even between each container for each cylinder. - No change noted. 8. Installed new intake gasket to #2 cylinder, inspected #2 intake tube lower o-ring. Pressure tested intake system with shop vac. - No leaks noted other than several pin holes in bellows gasket between fuel injection body and aircraft cowling/air box. No change noted during flight test. 9. Cleaned fuel injector body fuel inlet screen. Flow checked fuel flow indicator by disconnecting fuel line going to flow divider. (merely wanted to check accuracy of fuel flow indicator.) Small bubbles noted going through clear tubing during this check. Thought bubbles to be coming from AN union connecting clear tubing to aircraft fuel line that was only finger tight for my test. Regardless, air in the fuel system would most likely cause a different issue than what we're experiencing correct? At this time I also flow checked all the fuel manifold tubes in graduated containers for 2 minutes and the results were as follow. At a flow of 5.9 to 6.0 GPH, cyl #1 = approx 175ml; cyl #2 = approx 200ml; cyl #3 = 175ml; cyl #4 = approx 175ml. Just on a side note, I happened to notice oil residue at the bottom of the #2 intake tube. It does not appear to be in the lower air chamber located just aft of the fuel injector body. Also, during each flight test the difference in EGT between the highest cylinder (typicallay #2 ) and the lowest (typically #1) increases with increasing manifold pressure. We don't see the high EGT issue on the ground or during the engine run up before takeoff. It's starts to show during the full power during takeoff and continues all the way until power is reduced for landing. During one of the last flight tests with mixture full rich and RPM at 2500, the following differentials in EGT were recorded. 15 inches MP = 80 degress diff 17 inches MP = 90 degrees diff 19 inches MP = 120 degrees diff 21 inches MP = 130 degrees diff I hope all this information helps and if you still need borescope images from the #2 cylinder side walls I can obtain them yet this week. Our annual inspection is due at the end of this month and ultimately we would like to know what actions if any will need to be done as we've thoroughly gone over all the basic items and is proving to be rather frustrating. Could it be possible that our oil containment ring has cracked and oil is getting in to the cylinder causing this issue? I look forward to hearing from you soon. Kyle

Marauder, I had the two connectors off when trying to find the JPI download port. Turns out the installer of our JPI wired the download connector by the copilots knees in an easy to reach area. Haha. Wish I would've known sooner but I can confirm that these connectors are attached securely. I've also looked at all the yellow wires going to the firewall from the exhaust stacks and there doesn't appear to be any signs of chaffing or a damaged wire. Like Shadrach said, by swapping probes and leads I thought we verified that the #2 cylinder EGT is definitely hot for some odd reason. When I talked to the JPI tech rep he said this was correct. His exact woods were, "If you've swapped probes while leaving the channels to their respective cylinder and it didn't change THEN swapped the yellow wires coming from the JPI between the #2 probe and the #4 probe and the #4 indication on the JPI says its higher than the rest, you've got a high EGT. Time to start looking at the engine and talking with your engine tech rep because your JPI is working correctly. " He said a bad/shorted probe looks like a totally dead/cold cylinder and that our type of EGT probe doesn't use a ground through the exhaust stack. So a bad exhaust gasket isn't the culprit. I must say that I concur.

I would agree that 1280 is target for climb at sea level. Typically we're somewhere around there during our climb but not lately. These days #2 is somewhere around 1400 during the climb at 110kts. (Fear not the CHT's are all well below limits.) Typical fuel burn at 100 ROP is about 11.5-12.0GPH for us and we lean the #2 (hottest) cylinder to 1380. That's full throttle, 2500 RPM and 100 ROP. That was then, 14-15 is what we're at now with those same settings. Somethings up and like the topic implies, "It's not the probe" Fuel flow is being measured with the JPI. I flow checked it the other day and believe me, it's spot on. I'm not saying that 14GPH is unusual at high power settings, but for the given power setting above and what we're used to seeing, something is not right here.

Time to get the ball rolling on our EGT issue again. We're almost due for annual and I'd REALLY like to get this thing figured out. I did a cross country flight the other day and burned an asinine amount of fuel with the #2 cylinder leaned to our usual 100 ROP EGT number of 1380. All other cylinders are at or around 1280 and I want to say I was burning 13-14 gallons per hour which is WAY too much for an IO360-A1A. I'm hoping to start on my instrument rating soon but with this high EGT I'm a little hesitant. I'm MORE than convinced that it's not a JPI issue and the EDM 700 is doing exactly what it was designed to do by telling us that we've got a hot exhaust coming from the #2 cylinder. Now, I know this is a stretch but since we have good compression, no burned valves, good cleaned fuel nozzles, plenty of fuel pressure and flow checked fuel flow divider/nozzles, what are your thoughts on a broken oil scraper ring? The JPI data for that flight shows this whole increase of 100 degrees EGT on the #2 cylinder happening in a matter of seconds so SOMETHING must have happened or broken. We haven't done enough flights to determine a high oil consumption yet but if the scraper ring is broken I'm not sure we really want to be flying the thing just to see. The golden question is what makes ONLY the EGT on one cylinder to increase on a lycoming in a matter of seconds like that?

Just out of curiosity, did you turn on the JPI after you swapped probes and if so, what were the readings?

Update: I flew her again the other night and our issue still exists with the high EGT on the #2 cylinder so I decided to dive in again this weekend and see what I could find. The day before I gave a call to both JPI and Lycoming. JPI says due to the troubleshooting that we did by swapping EGT probes/leads, we definitely have a hot cylinder. When I asked about an induced voltage being applied to that particular probe/line he once again said that with all the probe swapping we did, it's not a possible cause of our issue. He said the probes are the ungrounded type and when they fail, they tend to do so in such a way as to give either a "colder" indication than usual or no indication at all. I would have to agree that the probes are fine and the cylinder is hot. I followed up that phone call with one to Lycoming and while the tech rep wasn't the most helpful guy in the world, his thoughts stray away from a valve train issue and lean more towards a blocked fuel nozzle/flow divider or an induction leak. I took her apart yesterday and took a look at the screen on the fuel injector body. There didn't appear to be much of anything inside it other than a little tiny bit of fuzz so I cleaned her out and re-installed it. I followed it up with another fuel flow test with the nozzles disconnected (fuel coming straight out of the 1/8 inch stainless lines.) After two minutes of running the boost pump i checked the containers and there were tiny specs of black stuff in a few of the containers Although I'm not quite certain where this debris came from my guess might be either residue from old fuel that had boiled in the manifold line, the flow divider or perhaps even the diaphragm from the injector body but I believe the diaphragms in my injector body are the metal kind(due to the OH date). I happened to stumble across this forum which has help shed some light on our issue so I'm off to the airport again this afternoon for some more investigating. I'll let you know how things turn out and until then I'm keeping my fingers crossed!

Friday I had the opportunity to test this theory of an alternator induced voltage in flight. I can definitively say that's not our issue as pulling the alternator field CB many different times didn't affect the CHT or EGT of the #2 cylinder and the JPI data shows the voltage going down to 0. I just don't see how your theory could be correct here Jose. I'm sorry if it seems rude, but I feel like we're beating a dead horse with that one. =/ I checked peak EGT during my flight the other day and #2 was around 1650 degrees. That's nearly 175-200 degrees hotter than the rest peak at. I'm literally going bananas trying to figure this one out. Lycoming says fly it but when the JPI starts blinking "150 DIF" constantly during climb and cruise it's kinda hard to ignore and feel comfortable flying with. My final question to you all. Is it possible that we still might have a fuel issue here? My only reason for asking is because we had Weep No More patch a leak in our fuel tank shortly before this issue began happening. You would think if there was any debris in the tank that it would've gotten filtered out before it got to the flow divider and "plugged the #2 cylinder fuel line" wouldn't you?

I think I see what you're talking about. After giving what you said some thought, I took another look at the flight where we first saw the high EGT issue. I noticed the CHT's on cylinders 2 and 4 look rather "noisy" as they fluctuate way more than the CHT's on cylinders 1 and 3. I'm not sure the same can be said about the EGT's but it certainly does lead one to think you might be on to something José. The weather has been complete garbage the past two days and doesn't look to be getting better until later this week. I've bumped up the recording interval of the JPI and we'll test out your theory when the weather shapes up. One quick note though, the alternator CB is the recessed type and can't be pulled in flight. Could a guy pull the ALT FIELD circuit breaker to do this test instead?

I can ask him tomorrow but it would see odd for him to switch tanks twice like that. Then again, I don't know where he planned his fuel stops or his personal flying preferences/techniques.

I believe this would've ruled out your theory of it being a grounded probe. Also, since the JPI probes are shielded alumel and chromel thermocouples, wouldn't a ground/short give us an extremely low EGT indication?

Dave here is the in flight induction leak checks etc. that we did. https://www.savvyanalysis.com/flight/909304/3faa364e-3150-4c9d-a3a1-6177ecf13711

This would have been the same flight only reversed. Was too high on my first approach and then did a go around. Hence the two large spikes in fuel flow.

Flight #563 was done by me. It was a short hop from a small grass strip to our home base and I was cleared for a straight in final. It was a tad windy and all kinds of adjustments were made. Our recording rate for the JPI is set to 6 second intervals and for that reason I'd consider the data up to the climb and just shortly after to be anything worth noting. I posted that flight to show the before and after effects of swapping the probes and thus ruling out the thought that it was a probe giving us the issue.

That I'm not sure about. That particular flight took place when a different owner was flying. Are you talking about the two spikes/dips at 00:28 and 1:03 marks?

I would be inclined to agree with you on a fuel distribution problem. Considering the probe troubleshooting, new gasket on the #2 intake tube and compression check of 78/80 I'd have to say its a fuel nozzle. However, we swapped the nozzles between #2 and #4 with no change so next I'd be inclined to think it's in our fuel manifold/distribution tubes or perhaps something to do with the fuel injector itsef? I haven't pulled the fuel injector screen since last annual but it might be next on our list of things to check along with pulling the rocker cover and checking for a damaged spring/loose valve. Any other thoughts/suggestions?

That I did. I physically did the labor and flew both of these flights so I can confirm that it's not a probe. =/ Here's the flight where we physically swapped the #2 and #4 probes but left the leads the same (#2 on the JPI still read #2 cylinder) https://www.savvyanalysis.com/flight/909301/a0e24670-c5cb-404a-8acf-1dbfaf61f84b And here's the flight afterwards where I left the probes hooked up to their respective channels (#4 on the JPI would be reading the #2 cylinder and vice versa) https://www.savvyanalysis.com/flight/909302/30752cab-4741-417b-8da1-30353819efb9

Here's the link to the Savvy Analysis page. Let me know if it doesn't work as I'm fairly new to this download data. First indication of high #2 EGT https://www.savvyanalysis.com/flight/909290/0b7cfa44-4d8a-4fc1-8b1d-e351520276c0 Following flight https://www.savvyanalysis.com/flight/909291/4081b956-abf9-4d21-8494-3e2b15460c1f Following flight https://www.savvyanalysis.com/flight/909292/2f5606ab-6aa6-4ba7-86b6-e8b56aff3df6

Opening the rocker cover and taking a peek is the only thing we haven't looked at yet. Hopefully we can get at it this week and come to a conclusion with this frustrating ordeal. Thanks for the input!

As promised, here's the JPI data from the flight where the issue first began happening. I've got to agree with teejayevans on this one. The JPI data is supporting evidence that something happened. The question still remains as to what exactly it is that happened though.

Hello to all and thanks for your input on this issue. I'm one of the other owners of Super Dave's super mystery Mooney. I'm also an A&P/IA Still hoping we can get to the bottom of this issue as I for one am totally stumped! To rule out a possible injector issue, I swapped the injectors between the #2 and #4 cylinder and still no change. I've also flow checked all 4 fuel injector nozzles for 60 seconds. I had the external power hooked up, had mixture and power levers full forward and our JPI was reading about 6GPH during my test. All four injectors measured out approximately 150cc's of fuel during this test so I think it's safe to say that it's not an injector. As Dave mentioned, we swapped the #2 EGT probe between cylinders #2 and #4 in every such combinations that I can confirm the probe is working correctly. I have borescoped both #2 and #4 cylinders and other than #2 appearing a little more wet than #4, I don't see any issues. I don't recall seeing any scoring to the cylinder wall and the cross hatching is still visible as well. However I did notice some oil in the bottom of the #2 intake tube and there some deposits near the exhaust valve on the #2 cylinder. More-so than the #4 cylinder. Is it possible that the #2 cylinder intake valve guide is worn enough where air is getting through it? I know it's a stretch but at this point we've ruled out all the obvious causes of our issue. Just last night I put a new intake gasket between the cylinder head flange and the #2 intake tube and still no change. I was going to change out the lower orange o-ring on the #2 intake tube but it's impossible without removing the entire exhaust first. There don't appear to be any cuts, nicks or flat spots on the o-ring so I think it's okay. I have most of these borescope videos saved to my Google Drive account and would gladly share them if you would like to take a look. Today I plan on downloading the JPI and graphing out the flight where the issue first happened in hopes that it might show us something but at this point I'm not sure what to do next other than opening the rocker box on the #2 cylinder and taking a look. I'll share the JPI data later too if you think it might help. Thanks in advance! -Frustrated Mooney Mechanic