Quote: "5. During the test, the #1 had the intake valve open."

Like I stated before, if you have a burned/bad/leaking valve in #3 then the air can escape back thru the intake maifold to #1. AND if that #1 intake valve is open during the test, then the air is going to go into that cylinder.

 

Since #1's compression test is the same as #2 and #4, and I didn't get any 0301 so I assume #1 works normally.

What if the #3's intake ring gasket broken? Could the air leak into the intake manifold and somehow get into the #1 when #1's intake valve is open?

 

This really is not making any sense. At #3 (true)TDC, #1 is at BDC, just after power and before exhaust(exhaust valves might be open[doubtful], intake valves closed).

Even if you were at false TDC(actually #2 true TDC), #1 would be at BDC, just after intake and before compression(all valves closed).

But why are your #1 intake valves open at BDC? The intake cam is towards the front of the car. Perhaps this is the point of confusion? Maybe it was the exhaust valves that were open(again, I doubt that any valves should be open at BDC)?

The cylinders are numbered 1-2-3-4 from passenger side to driver side. Firing order 1-3-4-2.

 

A. you said #1 intake was open
B. #3 has low compression
C. when #3 is pressurized you can sense air coming out of #1
D. there is a connection; if #3 intake is leaking air would flow through the manifold to #1

QED #3 intake valve is somehow leaking.

 

But there was no issue with low compression in #1?

Do you see any flaw with the way I've calculated which stroke, valve positions, etc?

I'm still nagged by the compression test suggesting rings, but the leakdown test NOT blowing air through all the oil passages in the head?

 

I'm just taking his statements at face value. If 1 cylinder has an open intake and another is pressurized and a sound is heard from the one that is open; air is travelling via the manifold not some mystical wormhole.

My brain can't do logistics right now.

 

If firing order is is 1,3,4,2. Then there would be valve opening cross over.

 

But do you think any valves are open at BDC?

 

#1 exhaust will start to open at the bottom of the power stroke

 

Yeah, I'm thinking #3 went a little past TDC, #1 a little past BDC, Exhaust valve open, #3 exhaust valve burned