Dilemma, no compression 0% leakdown

[Rusty 356]

This week we removed an engine from an 84 CArrera to replace the clutch and correct an intake gasket leak in the process. As well as a valve adjust. During the valve adjust
I found #5 exhaust to be extremely loose, I reset all the valves using a dial indicator,
0.10mm clearance.
Engine back in and running rough, pulled the plug wire on 5 and no change in rpm.
Did a compression check on #5, zero psi, did a leakdown, zero leakage.
Checked #6 everything as it should be.
Can't get my head around no compression and zero percent leakdown.
Pulled the valve covers off thinking that the problem may be a broken rocker or rocker
foot, everything normal. Exhaust valve was tight, reset with feeler to 0.004".
Any ideas on what is haunting us on this problem would be appreciated.
Best regards to all the birids,

[john walker's workshop]

can't have O compression and no leakage at the same time. do you mean 100% leakage?

[Rusty 356]

Above comment, I absolutely agree. Other than being humbled today. Here is what I have found since my post. When I adjusted the valves with engine on the floor, #5 exhaust had about 1mm of clearance, I adjusted to 0.10mm ( I thought).
The issue with the leakdown is that the same lead was used when checking the compression. One way check valve in lead.
When we pulled the exhaust cover a bit ago, #5 was tight. Readjusted and checked compression,
all is well. Now to put finish assembly and run again this evening.
My concern now is why the exhaust on 5 was loose then too tight. Will report my findings in the morning or later this evening.
And John workshop, I am in total agreement with your statement above.

[Bob Kontak]

Originally Posted by Rusty 356

The issue with the leakdown is that the same lead was used when checking the compression.

Given my experience of a small handful of leak-down tests, you don't use a one-way valve. The lead is free flow.

[Steve@Rennsport]

With 100% leakdown, you can easily hear the source,....

[yelcab1]

Originally Posted by Bob Kontak

Given my experience of a small handful of leak-down tests, you don't use a one-way valve. The lead is free flow.

and therein lies his problem, which he recognized.

[Jcslocum]

Improper cam position. Loose valve seat.

Maybe?

Good luck, just throwing stuff against the wall.....

[HawgRyder]

Also...when doing a compression test...make sure you hold the throttle open the same amount for each cylinder as you test.
I have seen people get strange numbers by not opening the throttles.
Bob

[Rusty 356]

Want to thank all you guys for not flaming me on this one.
The car is runing as it should, now I'm a bit concerned about the possibility of a loose valve seat.
Will run her today and monitor the performance for a bit.
Thanks again, I belong to several forums, the Pelicans definitely one of the best.

[Bob Kontak]

Originally Posted by yelcab1

and therein lies his problem, which he recognized.

Yep - old news. Sorry.