New Rebuilt Factory Engine Issues

Dtaglila

First some history, early last year my original engine had chewed up the lifter and cam. Decided after much back and forth to go with a factory “0” time rebuild. Engine was received in June of 2020, and the installation and first flight occurred in September. The engine was installed with all new hoses and hardware. The first startup and flight was done following Lycoming service instruction. Flew for 2.0 hours with a higher then the rest cylinder temp on number 1. This trend has continued through the whole breaking period. Normal high temps are around 420 to 430 degrees during initial climb to 500 feet. Normally at reaching 500 feet you could lower the nose and cool the cylinder off, once cool below 400+ degrees the cylinder would not normally exceed 400 degrees. Also noted during the first 10 hours was hard starting and engine kick back during failed starts. Investigation found that both magnetos were approximately 29 degrees advanced. Adjusted both mags back to 25 degrees and the kick back and hard starting was better. Cylinder#1 continue to still run warm, conversations with Lycoming tech rep stated he was ok with the cylinder temp. He commented the soft limit was 435 degrees. He said he wasn’t worried about but to keep flying it. Fast forward to 42 hours and again the timing was off by 3 degrees? Number 1 cylinder still exceeding 400 degrees during the initial climb. Inspection of the plugs show cylinder #1 is running leaner then the rest. Compressions were performed cold #1 was 78/80 #2 76/80 #3 79/80 & #4 78/80. Talking with Lycoming they requested an induction leak check which is planned for this weekend. If no induction leaks are noted they Lycoming want me to have send the carburetor back to AVSTAR for evaluation. Reviewing the as run data sheet I noticed the mag drops on brand new mags at 124 RPM Drop on both. To me this is a little high, wanted to hear the chats comments to see if I am off base on my concerns. I am seeing at least that much or more currently. In the past I have done inspections and internal timing on magnetos and have never see them this high? After 42 hours I am just not feeling the confidence level I should have for a factory motor? I know this is long, but wanted the folks to have all the information of my issues?

empannin

With a carburetor hard to balance fuel flows. I would run it richer to keep #1 < 400 during climb. EGT's should be ~ 1200-1300 in climb. If they are higher you are likely too lean overall.

What is the oil consumption like?

For cyl #1 I would check baffling including the under cylinder baffles.

The mag drop is very concerning. Mag timing should not slip this quickly and 4 degrees is far over a short period. If it slipped twice that is even more of a concern (7 degrees total). I would insist on having the mags fully overhauled or replaced. Kick back may have damaged the mags or the coupler cushion too.

Dtaglila

Thanks for the input, when climbing the engine is full rich since I am at sea level. EGT’s are in the 1300 range on climb out. The #1 exceeds 400 during the initial climb to around 500 feet. Once it cools off it usually will stay under 400.

Oil usage as basically a quart in 15 hours. With the new motor I invested in a set of AIRFORM baffles, I also made sure I had no air gaps.

I feel the same way as you I don’t agree with getting new magnetos out of a box and have roughly 125RPM drop. I have installed new and overhaul units that were around 50 to 75 RPM drops. You can’t even talk to a person at Champion anymore!
Thanks for the words of wisdom.

empannin

I think it is possible to adjust the carb so that it is richer at sea level. If you are climbing out at 1300 EGT it would be a small adjustment if any. I would check carefully on the baffles including the underside baffles as these can easily be over looked.
I am not as worried about the mag drop. The drifting timing concerns me. Should not drift that much over those hours. Either there is a procedure error (which is tough on a lycoming) or there is something internally drifting.

Dtaglila

Update on troubleshooting per Lycoming technical. Removed the carburetor and air box, nothing was noted when performing the inspection and disassembly. Once the carburetor was removed we performed an induction leak test with no anomalies noted. Next step will be to ship the carburetor to Avstar to Evaluation. Sent Tyler an email yesterday with my concerns with the magnetos, still feel 125 rpm drop is excessive for a new magnetos. Will update the chat as things progress.

singhbam

We purchased brand new Lycoming 0-235L2C Cylinders for our Cessna 152.
The engine runs very hot
Eventually Lycoming told us with the new type of Cylinder wall treatment they have introduced
Higher Temperatures are a possibility.

Seneca38173

Dtaglila, sorry to hear you're having this problem. Per the overhaul manual the factory will perform a flow bench calibration on the carburetor, and then a test cell run on the completely-assembled engine before shipping it back to you. Both tests follow a sequence of power and flow settings spelled out in the manual and will generate a bunch of test data that confirms your engine is working as designed before it leaves the engine shop. If you don't have that data already suggest requesting it from the factory, and reviewing it with your A&P. If all that looks good (I've seen several cases where the factory data was a "fail," but they shipped the engine anyway...), and you have an engine monitor, you'll be able to repeat most of the test run on the ground and compare the factory data with what you're getting in the field. Good luck! Bob T.

Dtaglila

Update on the engine, at the direction of Lycoming the carburetor was removed an induction leak check was performed. No leaks were found the carburetor was returned to AVstar for evaluation. After two weeks and a lot of phone calls the carburetor was returned and I was told they richened it up a little. Reinstalled everything and flew it yesterday, some improvements in temperature. I can now pass 500 feet without #1 heating above 400 degrees. The temperature still exceeded my personal limits by 17 degrees, but overall it was more stable. Aircraft still continues to run rough to me, definitely not as smooth as it was when first installed. I have in the past stated I believe I have magneto issues. I calculate, I have adjusted the Mags about 7 degrees total in the two timing procedures. I have sent this and other data to Lycoming today and will wait for direction from them. Thanks everyone for your input, I know some think I am to picky, but along time ago someone very wise said they talk to you before they fail, I believe she is talking to me. Stay safe!

griff390

Dtaglila;

You are right to hold your ground. High temps in an air cooled engine are generally broken down into a few categories:
1. running too lean
2. insufficient cooling
3. excessive cylinder pressure << this can be a mechanical issue, or timing.

I know it's a lot of work, but can you swap a couple known good mags into the engine and test? Before you do, make sure you don't have a crossed or arcing plug wire. Also check for a dead wire or plug.

I find it unusual that only one cylinder is running hot. Could be mechanical (would hate for you to find a bad cam or a cam not degreed properly, but that would usually effect all cylinders). Could also be something like a temp sensor that's reading incorrectly. Try swapping sensors with another cylinder and see if the problem follows that sensor.

If neither a sensor or mag, I'd get a Lycoming rep involved. We pay big money for these engines, and trust our lives with them. They should be right.

empannin

Jim has great feedback. If this was an injected engine the first suspect would be the injector. At full power even an induction leak should not matter much as the MP pressure is so close to ambient. To be too hot you would need to be off timing, too lean or not cooling as Jim pointed out. Too lean is tough to do in a carbureted engine (for a single cylinder).

Does it run equally rough on both mags? New mags should not need that much timing adjustment in the first 500 hrs. I would have this overhauled at a good shop even if new and have the timing process video taped on next install.

You are not being picky at all. It should purr like a kitten with no compromises.

Do you have any engine data you can share. What is your full power fuel flow? All EGT's should be in the 1300 range on take off.

Dtaglila

Thanks for the input, went out last night and performed a cold cylinder test. The meter showed temps within 8 degrees spread. Based on my experience I feel the plugs and harness are good. I am still concerned with the Mags. I have left a message with my Lycoming tech rep that I am done playing. Champions service letter states if the mag drift exceeds 5 degrees it is grounds for evaluation. Since in two adjustments I am around 7 degrees they either have to authorize me to send them out for evaluation and repair or send me a new set. I have already spent way to much time waiting and working on this motor. I know stuff happens, but I just want to be enjoying the airplane not wrenching on it so much. Waiting on Lycoming to provide direction?

empannin

One other test you can do (if you have not already) is lean out the engine and run at mag check power settings on a single mag and seeing if it is smoother on either one.

I have read again from the beginning and the one thing that really stands out is kickback and rough running. If the mags were mis-timed originally they could have both been damaged by a kickback event. To get kick back it really has to be incorrectly timed and although it could be valve timing it is more likely ignition timing - especially since it responded to changes in timing.

Here is a TCM Service Bulletin I found on this. http://www.tcmlink.com/pdf2/SB16-6.pdf

FYI: The TCM starter adapter was originally a medieval torture device adopted for engine use. It combines high orthogonal torque loads, a dodgy spring, and dubious compatibility with PM starters all in a compact, wildly expensive form factor in 15+ different configurations.

Also:
https://www.qaa.com/magneto-troubleshooting-guide
https://www.bonanza.org/community/member-forum/general-discussion/posts/mar-2018/start-on-the-left-mag/
https://www.aircraftmagnetoservice.net/magneto-troubleshooting-guide
https://www.casa.gov.au/file/79426/download?token=P1wnoPhv
A picture from the last link which covers many failure modes

Dtaglila

Thanks for the insight, to clarify the kickback occurred when I stop the start sequence and the right mag was hot because I let off the key. The starter was not engaged. As for the plugs and harness, I inspected the plugs and they all were normal also ohm’d them out and none of them exceed 3K Meg ohms. I have not tested every ignition lead, performing the cold cylinder check should have shown a bad lead in my experience? I can try your method to see if I can see any difference. When this started it was more noticeable after about an hour in the air. That is why I keep thinking it is something breaking down? I will update you soon as I get a chance to try it. You were correct on the kickback, both Mags were 4 degrees advanced over the specified requirements of 25 degrees. That was repaired with about 11.0 hours on the motor 30 hours later it was approximately 3 degrees advanced again? The rough running occurred during this time.

Dtaglila

Just off the phone with Lycoming tech rep and was told for warranty I would need to purchase 2 new magnetos and ship my current two Mags back for warranty clarification. Wow, what service I have to put out an additional 3K on my 30K motor to get it fixed. I don’t know why anyone would do that? I totally understand that is how the warranty is written, but with spending this kind of money I was hoping to have a top notch engine to where I wouldn’t need to worry about issues. The issue I have is the warranty words that stated if I did anything outside of what Lycoming directs I could void my warranty on the engine. I want to send the magnetos out to Aircraft Magnetos for evaluation and repair and was told if I do that I void the warranty on the Mags and possibly on the motor. Can we say your hands are tied? Frustrated, as an AP with dealing with a lot motor changes this has to be my worst experience I have ever had with engines.

griff390

Dtaglila;

Sorry to hear what you're going through. It's safe to say that if we had to go through what you're experiencing, every one of us would be just as frustrated. Wish there was more we could do. Please keep us updated.

empannin

I am sorry this has ended up so complicated with Lycoming. If you have to buy new replacement mags out of pocket that does not seem fair.
Can you confirm:
1) It will idle at the right idle rpm (even if rough)
2) When you lean it out the rpm will rise before the engine cuts out. At least 25 rpm.
3) I agree on the cold cylinder test
4) Does it run the same on either mag?
5) Is there a possibility the timing is off? Could the flywheel markings be in the wrong position? What process was used for timing?

Dtaglila

I agree, would be cheaper to repair them then replace the magnetos, they might be better. At 650 rpm the engine lopes, I did check for rise after the carb work, I am seeing a slight rise at shutdown. It does run slightly worse on the right Magneto. I have timed the magnetos to the engines but haven’t verified internal engine timing. Though the engine was good in the beginning. I still believe it is in the magnetos.

empannin

did you time off of the flywheel markings or by the piston #1 TDC? Wild theory that the flywheel would be incorrectly marked.
another thing to try would be pulling carb heat at idle to see if it runs smoother

https://resources.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2013-11_rough-engine.pdf

More Lycoming guidance:

https://www.aviationconsumer.com/maintenance/carburetor-idle-issues-check-the-mixture-first/

I found another reference somewhere for unusual roughness. In this case it was a small air leak on the fuel feed to the carburetor that would bring bubbles to the system and lean out the mixture.

You could also consider a LOP mag test where you run at 65% lean of peak and switch mags. This test is very good at picking out and weakness in plugs and harness but might be indeterminate if there is a systemic timing issue. If the engine dies on one mag go to mixture cutoff as the raw fuel can explode in the exhaust if you go immediately back to the both mags.

This test is more conclusive at altitude but can also be done on the ground.

Another mag article
https://www.kitplanes.com/magneto-timing/

What is the exact engine model? and what is the dataplate compression and advance? There are some engines that are 23 or 20 and not 25.

More info on timing:
https://www.lycoming.com/sites/default/files/Engine Timing Marks.pdf

griff390

Dtagilia;

Eric's post reminded me of one other obscure thing to check, the gascolator gasket. Usually they will leak fuel out, but they can also suck air in, and in severe cases, can cause engine stoppage.

empannin

Jim, good point. Another test would be with/without the electric boost pump. Also, are there fuel lines with different routing or lacking a heat shield? This could be a factor if it is worse hot.

Dtaglila

Thanks for the suggestions, I will investigate all of them. Right now working on a list of possible cause and will start working them one by one. The suggestions you provided will be on the list. Still have a tough time with the way Lycoming handles warranty work? I would think their customer service would be top notch especially when you buy a zero time motor. At this point with 20/20 hindsight I would have paid more to have my original engine done just to have the great customer service I have gotten from Don George Engines in Orlando. Thanks everyone for your comments, I just want to get it fixed so I can continue to enjoy it.

SoaringEagle

You might also have your A&P check the valve clearances on the number 1 cylinder. They should be between .028” and .080” for both intake and exhaust valves according to the Lycoming Overhaul Manual.

larmes502

We had a problem in a Cherokee 6-300 that turned out to be an oring in the gascolator admitting air bubbles into the line.

Dtaglila

ThanksI will add that to the list to inspect. As for the valve clearance, I will have to wait for the factory to authorize that inspection but will add that to my fault tree list.

hschulman

1) In regards to your warranty issues, stop fooling around with Lycoming and call the CEO of Textron.
I had issues in the past with service and warranty issues.
Call to the CEO on two occasions resulted in quick, and
Satisfactory resolution to both problems

2) Pull the left mag, make sure the gears are properly
Indexed if they are off one tooth the timing will
be off.
3) For timing use time rite or the eastern gauge, the
Ring gear may not be properly indexed.
4) As far as checking the valve clearance the limits
In one of the above posts, those clearances are
for dry tappets and that would require disassembly
Of the valve train to remove the oil from the tappets.

Note: When you receive your mags before installing
Check the mag cam for proper lube before
Installing them. Insufficient lube will cause
Rapid wear which causes timing drift.
I hope the above diatribe is helpful the the one thing I am sure about is usually the CEO warranty is better
than the written warranty. Good luck on getting your
Issues resolved

Dtaglila

Good morning everyone who has commented on my issue. Update to what has transpired over the last few weeks. Met with another A&P who is a motor guru and we came up with items to check and or replace. This list included quite a few items including item suggested here on the forum. First thing we did is remove the harness caps and performed a high voltage check on all the leads, we also cut all the tie wraps from the harnesses. All testing of the leads were nominal. While the caps were off we did some testing on the Mags, timing check, checked with pin to assure they were stabbed correctly all was within spec. Removed and replaced all the spark plugs, though they looked good I wanted to start from new, while replacing them I also cleaned each lead with acetone to assure they were clean when I installed them into the plugs. We also performed a complete fuel system check looking for any forms of leakage. One of the suggestions was on the Gascolator gasket, we inspected it and though it showed no sign of leakage we went ahead a changed it anyway since I had new gaskets. The primer system was pressurized and checked with no leaks found. The EGT probe on #1 was in question on my EI Engine monitor, I suspected it reading low, so since I had spares I just R & R it while I had the cowling off. As stated before, the engine lopped at idle and sometime hard to start. Everything under the cowling was scrutinized. On the initial start up the engine was smooth and the idle lope had stopped. Magneto checks still showing about 110 rpm drop on both. Some minor carburetor adjustments were made to mixture and idle prior to installing the cowling. Going to fly it a few hours before making final judgement on the engine will update you later this week.

empannin

Was any further adjustment to timing made? Encouraging that idle is now smooth. 110 drop is on the high side but if it is even between Mags I think ok. Does not explain the prior mag drift.

Dtaglila

Good evening, I basically started from scratch, pinned and reinstalled both Mags. I have no explanation on the drift, or why the Mags have so much drop. I have a spare set of AIRBOSS harness thinking I might install them temporarily and go do a mag check to see if anything changes. The # 1 cylinder is still heating up on climb out. Max I have seen is 424 degrees. Aircraft like I said is starting better with no idle lope. Those two things make me much happier. I have contacted a shop to see about dynamically balancing my prop. Still have a slight harmonic vibration at the yokes. Besides swapping the harnesses the only other thing we are considering is doing a dry valve clearance check. Thoughts?

empannin

What are take off fuel flows now at max power? How about EGT's?

Dtaglila

Thanks for the question, I don’t have a fuel flow meter, so answering that question would be a guess at best. The EGT are under 1400 during the climb out. The Dynamic balance corrected the prop unbalance from 0.49 IPS to 0.07 IPS. Engine smoother, but have times of being a little rough, then clears up and runs smooth. Still think, since I have a spare set of changing the harness just see if it makes any difference?

empannin

Might still be a little lean if 1400 on climb out. How hot it the air and fuel? Does the roughness clear up if you turn the pump on? That is a nice improvement in prop vibration.