Issues with new Lycoming

[RobertGary1]

After a bit over 10 hours still frustrated with this new engine. Paid a lot more to buy from Lycoming reman and was hoping to spend my weekend flying rather than working on it.  EGTs are still running Christmas tree style #3 running much hotter. Sometimes only 100F spread sometimes 300F diff. Will call Lycoming again Monday but I'm hoping the next step is for them to accept the divider and injectors back for bench testing. So far I've tried

Swapped plugs

in flight mag check 

swapped egt probes

soaked #3 injector. 

 

Im sure Lycoming will have me do a flow test next but since the problem only happens in cruise and climb out I don't think I can get sufficient flow from the servo without flow across it. 

Anyone else work through this? Any suggestions for working with Lycoming?

 

-Robert

[jetdriven]

They will probxbly tell you that it is normal and they don't guarantee an EGT spread. I did convince them to give me a new #2 injector, not because the spread was 100 degrees but because the cap fell off.  They said run it 50 ROP I said how do I do that if one is 50 ROP the rest are 150 ROP.  I had to buy GAMI injectors and with the richest injector they sell in #2 and the C and D injectors in the other holes it's 100 LOP on #2 when the others peak  

Dont give up, don't accept the support rep as final. Keep escalating it  

 

Edited September 19, 2015 by jetdriven

[RobertGary1]

I have the logs from the old engine and with factory injectors I was rarely more than 50F off. This is disappointing. At worse that #3 is going to have a short life and at best I'm going to be running an extra gal/hr. 

 

-Robert

[N601RX]

The 300 sounds a lot like only one plug firing. 

[Super Dave]

What are EGTs peaking at? What is your GAMI spread?

[Marauder]

Does the JPI do data recording? If so, it might be good to start sharing that data with them and others who can provide a collaborating perspective on what you are seeing. 

[MB65E]

I'd check the timing. Make sure it's at what the data plate says. Ohm test the spark plug leads to the back of the mag harness in the mag. Then see if you can get an ignition tester. It will basically load test the harness. Flow test it with the injectors off, and then on but not installed (in the engine). Could also take the injector apart if you have not already. Separate the stainless insert from the brass piece.  Finally,  make sure the prob is installed on the stack in a similar spot as the others...But it's probably your existing exhaust 

Let us all know what you dig up. 

Cheers!

-Matt

[Shadrach]

I have the logs from the old engine and with factory injectors I was rarely more than 50F off. This is disappointing. At worse that #3 is going to have a short life and at best I'm going to be running an extra gal/hr. 

 

-Robert

Robert, have you tried doing an in flight mag check at high power? I don't remember if we talked of this before.  I think I've already said that I believe this is ignition related. I doubt it's a timing issue as it would likely be more consistent across all cylinders if it was.

[ArtVandelay]

What about the CHTs?

[jetdriven]

All 4 of my intake tubes were leaking at the gasket at the head.  This last annual, I replaced the two on the right side and fixed a large vacuum leak.  If the EGT spread is larger at part throttle than full, it may be a symptom. 

[N601RX]

My engine is approaching 3 years old and timing is set to 25 deg. I've kept the engine monitor files since the 1st breakin flight. I'm close to sea level and when full power, full rich egt's have always been around 1200 deg.  The peak EGT has always been around 1420 deg for a difference of around 220 between full rich and peak.  The only time I have ever seen the egt go any higher that this was one time when I accidentally took off with the mag switch set to left instead of both.  After landing and figuring out what I had done, I went back up and did a few quick test.  No mixture setting would produce a egt higher than around 1420, but either mag off would make them jump to 1500, for a difference from full rich of about 300 deg.  Another clue to the ignition problem was the egt's varied around a little and was not be as stable as normal.  If your engine monitor has data logging set it to 1 second and go fly for a while. 

[RobertGary1]

Looks like the next step is to flow test. I'll flow all 4 lines without the injector first and then I'll probably just flow test #3(hottest) vs #4(coolest) injectors. I'm thinking I'll then swap #3 #4 injectors and see if the problem follows. 

Idle is too consistent for it to be an intake problem. At take off there is almost no differential at the intake.

Its interesting that Lycoming provided me a sheet of all kinds of temps and measurements of my engine when they broke it in but they do not measure each EGT. They only provided the value they saw for #3.

-Robert

[Shadrach]

Looks like the next step is to flow test. I'll flow all 4 lines without the injector first and then I'll probably just flow test #3(hottest) vs #4(coolest) injectors. I'm thinking I'll then swap #3 #4 injectors and see if the problem follows. 

Idle is too consistent for it to be an intake problem. At take off there is almost no differential at the intake.

Its interesting that Lycoming provided me a sheet of all kinds of temps and measurements of my engine when they broke it in but they do not measure each EGT. They only provided the value they saw for #3.

-Robert

Lycoming is still measuring EGT the way they did it in 1965.

[Shadrach]

My engine is approaching 3 years old and timing is set to 25 deg. I've kept the engine monitor files since the 1st breakin flight. I'm close to sea level and when full power, full rich egt's have always been around 1200 deg.  The peak EGT has always been around 1420 deg for a difference of around 220 between full rich and peak.  The only time I have ever seen the egt go any higher that this was one time when I accidentally took off with the mag switch set to left instead of both.  After landing and figuring out what I had done, I went back up and did a few quick test.  No mixture setting would produce a egt higher than around 1420, but either mag off would make them jump to 1500, for a difference from full rich of about 300 deg.  Another clue to the ignition problem was the egt's varied around a little and was not be as stable as normal.  If your engine monitor has data logging set it to 1 second and go fly for a while. 

Interesting, we're flying the same engine and when full rich, I'm in the low 1100s across the board. I shoot for 1200 as a climb EGT unless things are heating up in which case I enrichen back down to 1130 or so. Max EGT changes with RPM. at 2700 mine cluster around a number close to 1500 (mostly high 1400s) at 2500rpm more like 1450. Of course as one climbs, max EGT decreases.  It's not an earth shattering difference, but I have approx 330 deg difference from full rich to peak. 

[neilpilot]

Interesting, we're flying the same engine and when full rich, I'm in the low 1100s across the board.

By this time, you must realize that comparing absolute EGT readings between aircraft is virtually meaningless.  One of many variables that will greatly effect readings is the placement of the probe; a short difference in distance from the flame front can result in major difference in indicated EGT for a cylinder operating under exactly the same conditions.  This difference can even effect comparison of indicated EGT (not actual EGT) between cylinders on the same aircraft, if the probe placements are not selected with care.

[Shadrach]

Yes, I'm familiar with the concept thanks!    Would you not consider it noteworthy that I have a 330df spread between full rich and peak whereas N601RX has a 220df spread. I'll chock it up to technique (it takes a little patience to find absolute peak EGT).  While the actual raw EGT values generally mean nothing (there are times when they are somewhat useful), I would say the spread does mean something. All other things being equal, the numbers would suggest that my engine is running richer. However, since we can't verify that all other things are equal, it's likely some other combination of technique, Field Elevation, DA and probe placement.

[EDNR-Cruiser]

Gents, RobertGary is not talking about a 300° difference between full rich and peak but 300° difference in EGT between the cylinders at exactly the same mixture and power and RPM setting. This is wrong and has to be fixed and he already checked that it is NOT the probe. So it's in the engine and no matter what Lycoming says, it is not normal.
No matter what I do, the EGT difference in my IO-360 is never more than 70°, mostly just around 20-30° between the cylinders.
 I would not rest before that is fixed.

[RobertGary1]

I went out to the airport to do some fuel diagnostics. First I flow tested all 4 lines (without injectors) at full throttle and mixture. Got 25ml with only about 0.5ml variance. 

I then pulled injectors and tested the streams. #4 (the cool egt) had a nice pencil straight stream (unlike cars automotive injectors don't atomize fuel). #3 was pissing about 30 degrees sideways and was somewhat scattered. 

So I soaked the injector again and tested the stream again. This time I got good streams. 

Did a runup and got only a 20 degree egt difference even at full throttle. Since it was after dark I didn't want to flight test it. I'll fly it Saturday when I do the first oil change. 

So fingers crossed but this problem has been inconsistent in before. 

If the problem is debris it's interesting to wonder how debris couldn't get in there from the Lycomjng factory  

 

-Robert

[AndyFromCB]

Maybe one day Lycoming and Cessna will get bought out by China and then they can move all production/overhauls to a 21st century facility with CNC machines ;-) Been playing a lot of high pressure solenoid valves in my latest project. The ones we source from China are vastly superior to anything we can get from USA or Europe. Only the ones from Japan are better but at 7x cost, not worth it. Ones we can source from US manufactures are pure junk. I don't need a microscope to see flaws on the balls...

[Andy95W]

If the problem is debris it's interesting to wonder how debris couldn't get in there from the Lycomjng factory 

Debris from the factory isn't as uncommon as you would think.  The good new is that it will eventually get better.

Since you are finding evidence of debris at your injectors, have you removed, inspected, and cleaned all of your fuel filters/strainers?

[aaronk25]

Don't get me started about lycoming and what happens when they delivery poor quality replacement parts (camshaft) that lasts 400 hours and 2.5years which necessitates a overhaul. Oh by the way mr. Customer you are 6 months beyond the warranty period. Screw you. Lycoming is a terrible company, in my opinion. Outdated engines.

[carusoam]

Really well documented challenge/solution starting with the wide EGT spread.

way to go, Robert!

best regards,

-a-

[RobertGary1]

Soaking #3 brought it right inline! I also swapped 3 and 4 just for good measure. As you can see from the first pic 2 was high too. I pulled that injector and I could see debris in it. I blew it out but then soaked it for good measure. Also drained the break in oil and changed my fuel lines (would have been easier if I'd done it when I was installing the engine:)). How I'm getting 20 spread at take off power!! Saw 50 on downwind but If the spread stays under 50 I'll be happy. Very excited to feel comfortable leaving the local area finally with my new engine. 

If I didn't have the edm I probably would have just burnt some exhaust valves. 

 

 

[jetdriven]

There is there is no mixture setting that will burn exhaust valves.  

FWIW my rebuilt factory motor had trash in the injectors too and it took 3 rounds of cleaning them to get it all out.  They did such a good job tapping the holes that two of the injectors would torque up while upside down. After shutdown they would gurgle and burp fuel all over.   

[Shadrach]

Wow! I would have never suspected that factory new engine would be assembled with a fuel system full of debris. That is piss poor QC in an industry that cannot afford piss poor QC.

Did you contact Lycoming and tell them what happened? I'm sure they'll blame you or the installer, but I'd still try.