Engine issue?

Looking for opinions and advice for a possible engine issue.

I have had the 1931 Tudor for about three years and I know nothing about the history of the car or the engine. In the last few months a ticking noise has developed in the area of cylinder three or four. To my untrained ears it sounded like valve noise.

To try to figure out what to do (if anything) I started with a compression test which showed 59, 59, 40 and 61 psi. There is something going on in cylinder # 3! To confirm the compression, I did the testing twice more with almost identical result.

Next step would have been a leak down test, but I couldn't get my hands on a tester so I tried just compressed air into the cylinders to see if I could identify any leaking. Cylinders 1,2 and 4 lost pressure very slowly, while #3 lost air quickly through the exhaust at TDC when the valves should have been closed. What am I dealing with here? A sticking or burned valve or something else?

My ideas for next steps would be to remove the valve cover and try to see what is happening there. If that is not successful, removing the head would be the next step, but I would like to avoid that if possible.

What, if anything, am I missing with the diagnosis and what other options would there be for attacking the issue?
 
most likely from your description the exhaust valve is not seating properly, possibly starting to 'burn" ----when you remove the cover check the clearance ---if tight the compression may come back with adjustment if it has adjustable tappets ---otherwise the head comes off anyway
 
Might me able to see something with a borescope through the spark plug hole, might be able to see what going on along with condition of the valve/seat. Try cranking the motor manually and observing.
 
Might me able to see something with a borescope through the spark plug hole, might be able to see what going on along with condition of the valve/seat. Try cranking the motor manually and observing.
Not long ago someone had a similar problem what it was was carbon under the valve and they cleaned it up I think with Marvel Mystery Oil in the fuel and perhaps a little water in the intake of the carburetor

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If someone installed valve seats, it might have come loose.


I would never install valve seats unless the block is worn away.
 
i had a bad valve guide in my car/ replaced 2 valves and lapped all 8 of them, new guides and springs. now it runs better then ever!
 
I'm with Kurt. The side cover can be removed without taking off the manifolds and the clearance checked as well as for a sticky valve. I think thats the first place to look.
 
This issue has an unexpected solution. After the first post, I borrowed a borescope to try to figure out what was going on. Well, the valve didn't close (which I already knew), but it didn't seem burnt and there was no separate seat coming loose. I added more MMO and left it for a day. No change! Time to bite the bullet and pull the manifold and the valve cover.

Wouldn't you know it. The tappets were double nut adjustable and the lock nut had unscrewed. Of course the valve couldn't close! The tappets wouldn't let it down. I did not expect that at all, but I am happy that was all. The head stays on!
 
This issue has an unexpected solution. After the first post, I borrowed a borescope to try to figure out what was going on. Well, the valve didn't close (which I already knew), but it didn't seem burnt and there was no separate seat coming loose. I added more MMO and left it for a day. No change! Time to bite the bullet and pull the manifold and the valve cover.

Wouldn't you know it. The tappets were double nut adjustable and the lock nut had unscrewed. Of course the valve couldn't close! The tappets wouldn't let it down. I did not expect that at all, but I am happy that was all. The head stays on!

I find that a borescope, IR Temp laser gun, Napa Block test, and compression tester are worthwhile tools. They can tell you a lot and save time by diagnosing, instead of shot gunning trying things. Also give you some feel of the shape/condition of your motor and cooling system.
 
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