Sticky valve? Nope! Ignition? Nope! Oil canning? Maybe...

[bullojm1]

Originally Posted by erich weaver

The other common source is the bag of chips you threw in for that mid flight snack exploding at 10,000 MSL.

This has NEVER happened to me!

[Malndi]

So the oil can was oil canning?

Glad you sorted it out.

[Bevan]

Originally Posted by bullojm1

This has NEVER happened to me!

According my experience, a large bag of Ms Vickies salt n vinegar chips is calibrated to burst at 7000' pressure altitude. The delicious aroma was instant.

Bevan.

[RVbySDI]

Glad you found the true issue. It is too bad you started on the most expensive side, both in effort and $$, in your troubleshooting attempts. The good thing though is that after doing all those tests, upgrades, changes, etc. to the engine means you now have a great running engine and high level of confidence in its performance.

This reminds me of the adage that whenever troubleshooting a problem start with the simplest/easiest/cheapest solution and work toward the difficult/hardest/expensive solution. Many times it is those simplest/easiest/cheapest solutions that solve the problem.

[Brantel]

Originally Posted by RVbySDI

Glad you found the true issue. It is too bad you started on the most expensive side, both in effort and $$, in your troubleshooting attempts. The good thing though is that after doing all those tests, upgrades, changes, etc. to the engine means you now have a great running engine and high level of confidence in its performance.

This reminds me of the adage that whenever troubleshooting a problem start with the simplest/easiest/cheapest solution and work toward the difficult/hardest/expensive solution. Many times it is those simplest/easiest/cheapest solutions that solve the problem.

I agree. The effort was free but the $$ was not insignificant. However I was planning to add a second EI at some point anyway, this just accelerated that. As for the engine, I did find some goofs by the original builder that make all of that work worth it to me. I would have never found that stuff until it was too late if I had not torn into it. I also learned a ton about how the valve train works on a Lycoming. Hands on experience of all of that is priceless. The old cork gaskets on the rocker covers, oil drain and intake tube hoses were starting to leak as well so it was good to replace all that anyway. The intake and exhaust gaskets appeared to be OK but it definitely did not hurt to change them out as well.

As for what I would do different if I were starting over again, I am not sure. It was very hard to describe what was happening to others. It took some time for the patterns to become obvious. It was something you had to experience. The sound it was making in the air was very loud and very scary and for me the only thing I have every heard that was even close to that level of sound was an exhaust after fire bang. It was getting to the point where I was gonna have to find the issue or stop flying the plane because the noise was so loud and scary sounding that I knew it had to be something unusual going on and the fear was that it was some sort of pending disaster that I could not find.

In my defense...nobody ever recommended to check the smoke tank

The funny thing is that in my day job I am known for someone that always defaults to checking the easy, cheap stuff first as that turns out to be the problem 98% of the time.

[BillL]

Originally Posted by Brantel

In my defense...nobody ever recommended to check the smoke tank

Weak my friend - to our defense, you did not say you had a smoke tank with flat sides and no vent . . . . The possible description of "oil canning" was a red flashing arrow.

All in good fun, you are good company, the best part is you kept an open mind and went seeking better data.

[Brantel]

Originally Posted by BillL

Weak my friend - to our defense, you did not say you had a smoke tank with flat sides and no vent . . . . The possible description of "oil canning" was a red flashing arrow.

All in good fun, you are good company, the best part is you kept an open mind and went seeking better data.

It has a vent, just a one way vent....one way being it lets air in and does not let oil/air out. Even with the checkvalve/vent it it puts a slight vacuum on the tank due to the tiny spring holding the ball closed.

I talked with Marvin via email and he said I am #2 to report this issue (I am always the lucky one). He and I agreed that an overboard vent would be best and to ditch the supplied check-valve vent.

[Raymo]

At least you found and fixed a couple engine issues that could have developed in to real problems - especially the P-Mag stud hanging by 2 threads that were about to let go.

[Brantel]

Originally Posted by Raymo

At least you found and fixed a couple engine issues that could have developed in to real problems - especially the P-Mag stud hanging by 2 threads that were about to let go.

I agree, I am definitely happy to have found a few issues that could have been big trouble down the road!

[Jack Beck]

Nice work, Brian. The longer a problem takes to diagnose, the more satisfying the solution...or should I say the expensive is the solution.