Lycoming O360-A4M CLicking/Ticking

idahoflier said:
The mechanics that looked at the engine and replaced the pushrod tubes.
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Ask them to give you a list of the dry tappet clearance of each valve.

You've got one that the lifter is not pumping up far enough to remove the clearance in the valve chain of parts.

remove a valve cover, take a picture of the mechanism show it to us.
 
I agree with Tom primarily because it seems like the noise lessens as rpm increases toward the end of the .mpg, meaning as oil pressure increases, the hydraulic plunger pumps up. A longer .mpg at slightly varying rpm would help.

That ain't piston slap, and the frequency of the tapping seems a might high for wrist pin at that rpm. I'd take a mechanics stethoscope and ID the jug, pull the plungers, check for debris and soak them in cleaner.
 
Chip Sylverne said:
I agree with Tom primarily because it seems like the noise lessens as rpm increases toward the end of the .mpg, meaning as oil pressure increases, the hydraulic plunger pumps up. A longer .mpg at slightly varying rpm would help.

That ain't piston slap, and the frequency of the tapping seems a might high for wrist pin at that rpm. I'd take a mechanics stethoscope and ID the jug, pull the plungers, check for debris and soak them in cleaner.
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Hydraulic lifters pump them selves up, they do not depend upon oil pressure from the oil pump.
as long as the lifter is provided oil, it will pump its self up by filling with oil when it expands, then closing off the cylinder on the up stroke creating a hydraulic lock in the lifter.
 
A rod knock will sound a lot like this, but not for long.
If I could not locate the cause of this noise with normal trouble shooting procedures, I'd tear down the engine for rebuild.
 
You guys are true internet gods. You can troubleshoot an engine you’ve never seen better than the mechanic working on it.

Pure awesomeness!
 
Salty said:
You guys are true internet gods. You can troubleshoot an engine you’ve never seen better than the mechanic working on it.

Pure awesomeness!
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They’re offering suggestions and trying to help. I asked for help and I appreciate the comments they provided...
 
Salty said:
You guys are true internet gods. You can troubleshoot an engine you’ve never seen better than the mechanic working on it.

Pure awesomeness!
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There's your attitude again. can't add the the conversation, so just say something nasty.
 
Tom-D said:
A rod knock will sound a lot like this, but not for long.
If I could not locate the cause of this noise with normal trouble shooting procedures, I'd tear down the engine for rebuild.
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In my experience, rod knock doesn't get softer with increased rpm, it gets louder, and usually oil pressure will be low.
 
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Tom-D said:
Hydraulic lifters pump them selves up, they do not depend upon oil pressure from the oil pump.
as long as the lifter is provided oil, it will pump its self up by filling with oil when it expands, then closing off the cylinder on the up stroke creating a hydraulic lock in the lifter.
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They don't depend directly on oil pressure, but they do depend on the volume of oil passing through. Especially if there is debris or a stuck check ball. The higher the pressure and volume, the more oil can be forced past the check ball into the plunger...theoretically anyway. Otherwise, why would a noisy sticky lifter in an auto engine pump itself up and get quiter with increased rpm? In the old days, we would drain the oil and fill the crankcase with ATF and let the engine high idle for a short while. More often then not the ATF would flush the lifters clean and solve the problem. It worked because low viscosity solvent/lubricant was forced into the lifter by increased volume and pressure from the oil pump.

Let me be clear, before I get jumped on, I AM NOT RECOMMENDING THIS IN THIS CASE.
 
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Tom-D said:
There's your attitude again. can't add the the conversation, so just say something nasty.
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I stand behind my statement. Anybody that can troubleshoot an engine they've never seen better than the mechanic with hands on it is awesome. Sorry if you are offended by being called awesome.
 
Salty said:
I stand behind my statement. Anybody that can troubleshoot an engine they've never seen better than the mechanic with hands on it is awesome. Sorry if you are offended by being called awesome.
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Really ,, what else could you say.
Or are you trying to spin the thread again?
 
Chip Sylverne said:
They don't depend directly on oil pressure, but they do depend on the volume of oil passing through. Especially if there is debris or a stuck check ball. The higher the pressure and volume, the more oil can be forced past the check ball into the plunger...theoretically anyway. Otherwise, why would a noisy sticky lifter in an auto engine pump itself up and get quiter with increased rpm? In the old days, we would drain the oil and fill the crankcase with ATF and let the engine high idle for a short while. More often then not the ATF would flush the lifters clean and solve the problem. It worked because low viscosity solvent/lubricant was forced into the lifter by increased volume and pressure from the oil pump.

Let me be clear, before I get jumped on, I AM NOT RECOMMENDING THIS IN THIS CASE.
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Auto lifters don't operate in the same manor as aircraft lifters, Aircraft lifters must also pump oil up the push rod to oil the rockers, They have a check valve that allows this to happen. When this check valve malfunctions the lifter will never remove the clearance it is supposed to, the oil simply escapes the lifter no hydraulic lock occurs.
 
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Tom-D said:
Auto lifters don't operate in the same manor as aircraft lifters, Aircraft lifters must also pump oil up the push rod to oil the rockers, They have a check valve that allows this to happen. When this check valve malfunctions the lifter will never remove the clearance it is supposed to, the oil simply escapes the lifter no hydraulic lock occurs.
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C'mon' Tom, now you just arguing for argumen's sake. They operate in the exact same manner, and even have the same components, only they may be engineered differently. Each has a check ball, a socket, a valve body and push lube up the pushrod tube. Leak down rates may differ, but they operate exactly the same.
 
Salty said:
I stand behind my statement. Anybody that can troubleshoot an engine they've never seen better than the mechanic with hands on it is awesome. Sorry if you are offended by being called awesome.
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Well, if the mechanic couldn't identify the problem, how is it he is better than someone else (internet or not)? You clearly view everything Tom says from your negative perspective.

Agree with the others, your snarky attitude continues to pollute this forum.
 
Lndwarrior said:
Well, if the mechanic couldn't identify the problem, how is it he is better than someone else (internet or not)? You clearly view everything Tom says from your negative perspective.

Agree with the others, your snarky attitude continues to pollute this forum.
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I apologize to all. I missed this statement in my previous reading.
The shop believes the ticking is reduced but still present.
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Flybuddy said:
Is it possible that the Pushrod(s) are too long?
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too short maybe. this is why we do a "dry tappet" clearance check.
Too long the valve would be held open. and show a low compression reading.
 
Here is a typical 0-200/0-300 and normal Continental lifter assembly and how it works.
there are only 4 parts to the assembly.
1 the cam follower, note the two holes
2 the hydraulic unit, note the spring and plunger at the top.
3 the push rod cup
4 and the clip to hold it all together.
The cam follower of course moves up and down pushed up by the cam and down by the valve spring.
The hydraulic unit, sets inside the cam follower and moves with it, It does not move up or down inside the cam follower, the little spring and plunger at the top provides a small amount of pumping to provide oiling of the components of the rocker box, up thru the push rods to the rocker arms. It does not have any ball or check valve.
The push rod cup simply provides a place to seat the push rod.

As the cam pushes the cam follower up, it will close the lower port (holes) between the case bore and the cam follower creating a hydraulic lock in the cam follower (a valve of sorts) which provides the solid lifter effect to over ride the valve spring and open the valve.
At the very top of its travel, the upper hole in the cam follower aligns with another hole in the crank case bore and dumps the hydraulic lock, providing the oil flow in the lifter assembly.
The opening and closing the cam follower ports creates a check valve effect, There isn't really any separate valve, and certainly no ball.

First picture the hydraulic unit compressed
Second picture hydraulic unit expanded
Third and fourth the picture all 4 parts
 

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Mine plane is doing the same thing…

 
Chip Sylverne said:
Eau contraire! Nomenclature matters...a lot. Everyone may think what you pictured is a lifter, but it ain't. Replacing those is a major job. Replacing the hydraulic lifter is minor. It's easily removed from the Lycoming assembly by removing the pushrods and pushrod tubes. Just don't use a magnet and magnetize the check ball. I would check the dry lift at the valve, and if it's in spec, suspect the hydraulic lifter.
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I don't mind your nomenclature, but your French needs a tuneup!

Paul, remote from the French Canadian border...
 
Hello idahoflier, Searching the internet, I came upon your post. I am
experiencing the same ticking sound, O320E2D. Just curious if you
found what caused the sound.
 
76Skyhawk2 said:
Hello idahoflier, Searching the internet, I came upon your post. I am
experiencing the same ticking sound, O320E2D. Just curious if you
found what caused the sound.
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No I didn't. My engine was 26 years old, 1800+ hrs and had already had a few cylinders replaced. I had already spent ~ $500 trying to diagnose the problem and the theories for the cause ranged from lifter issues to piston slap. My flying includes a fair bit of flying over mountainous terrain so I didn't care much for a monitor approach. I planned to keep this aircraft for a while and I knew I would have to overhaul the engine sooner or later so I decided on sooner and had it overhauled. It doesn't tick anymore!

I have heard this exact sound a few times from Lycoming engines so I don't think whatever is causing the tick is an uncommon problem. My guess is that the sound was a collapsed lifter and probably would have been an easy fix once identified. But that's just a guess. If my engine was lower time I probably would have continued pursuing the issue. Good Luck!
 
Thanks for the reply. Whoever did the OH, did they mentioned if they found anything which would have caused the problem. Or, anything unusual about the parts, cam, connecting rods, pistons etc.
 
76Skyhawk2 said:
Thanks for the reply. Whoever did the OH, did they mentioned if they found anything which would have caused the problem. Or, anything unusual about the parts, cam, connecting rods, pistons etc.
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No, Penn Yan did the overhaul and new cylinders and cam are included so I doubt they took the time to inspect the old parts.
 
My bet is they DID inspect the old parts. After getting new jugs they called to say
that one cylinder had a flat lifter. They could tell by valve guide wear.
 
They knew I had installed then so they called me.

I’m glad they did.
 
Magman said:
They knew I had installed then so they called me.

I’m glad they did.
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Sorry, I'm not following? Are you saying you had a similar issue, replaced cylinders and whomever replaced the cylinders called you to tell you about a flat lifter?
 
No ticking.

Removed cylinders and sent to Penn Yan.

Cylinders were rusted so new assy were purchased.

Penn Yan called me to advise of a flat lifter based on what they observed in the guide.

Replaced flat lifter.

I installed new cylinders.

All is well.
 
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