Stuck lifter body.

C

cspencer

New member
I have a Lycoming AEIO-320-E2B installed in a 1976 7KCAB Citabria. The engine has 300hrs since major overhaul which included new camshaft and lifters. The case halves, crankshaft and connecting rods were inspected and yellow tagged by ECI. Penn Yan (.10 over) cylinders with new pistons, rings etc. (Total time on the engine at time of O/H was 1595hrs) This maintenance accomplished 4 years ago by a now defunct shop in NY.
The engine has run very smoothly with no problems for the last 2 years during my ownership, and has only been used for light aerobatics and has mostly been flown locally but has been used for a few 3-5 hour cross country flights during the last year.
Recently the engine was difficult to start, which is unusual, and when started ran extremely roughly. It was immediately shut down. On inspection the propeller turned easily( almost too easily). After removing the top plug from each cylinder, the #4 cylinder could not generate any compression. There was no air escaping the exhaust system. The left side valve covers were removed and the intake valve on the #4 cylinder was found to be stuck open with no movement of the pushrod on turning the prop by hand. The other pushrods worked appropriately.
The pushrods on the #4 cylinder were removed which allowed the intake valve to ‘snap' shut. The hydraulic lifters were removed and resisted compression in a normal fashion. The tappet ‘lifter body' on the exhaust side moved freely within the crankcase but the intake tappet was stuck and could not be moved even with moderate tapping with a brass drift. I have not received oil sample results yet.
I think I understand the implications of the above findings and that I am going to have to get the case split to get the final diagnosis, but does anyone have any insight as to what I should expect to find. Am I looking at another overhaul or even new engine? There will be no warranty consideration.

Best regards

Crispin
 
If I understand you correctly the lifter body is stuck in the case. How has your oil pressure been running. What kind of enviroment has the plane been exposed to and time between the last recent flight. What was the time hourly and days since your last oil change. For the lifter to be stuck in the case is not real good. I have seen them "pump up " and stick. AV Blend works wonders on this type problem. If it is stuck in the case you don't have a lot of options. The engine didn't get to hot at some point did it. You might want to call some of the engine shops they can probably give you more insight into just what your looking at.


Woodie
N29763
 
Woodie,
The engine had been flown within the last 10 days with no problems noted, and no overheating seen during the last 200 hours; oil pressure has been normal. The environment that this aircraft lives in is typical Southeast United States air temperature and humidity, even though it is hangared. I think that this engine is flown often enough and maintenance performed on an as needed basis. Oil changed every 25 hours with an oil filter in place.
Makes me wonder about Lycoming engines and oil additives(MMO and AvBlend), since 2 of 2 responses suggest their usefulness.
I am contacting engine shops.

Thanks for the post
Crispin
 
I saw a new O320 have a lifter stick this summer. I t bent the valve and pushrod. It flies pipeline and had come into the airport at night. The next morning the oil was to be changed, when cranked is when it happened. The engine was sent back to Lycoming and I don't know just what caused the problem. in your case the causes are not to great corrosion,rust,overheating, lack of oil on that one lifter"if possible" or a lifter that might have cracked some how and swelled. From what you say corrosion and rust are probably not the cause. Lack of oil or overheating would probably be more likely you realy want know until you get in there and see. Maybe your case is not damaged. Are you going to 0 SMOH ot IRAN? It would seem that if it were a problem with the last overhaul it would have already shown up. Anyway let us know what the "verdict" is when you find out.


Woodie
N29763
 
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