|
wait. You put the head on, with no cams. So the valve are closed.
Then apply 100-150psi to the cylinder #4.
And check the leak down while piston is BDC.
And you get 10%? Find out where it is going. Do not move on to the next step until you see where it going.
Before moving on, seal the crankcase so if any air escapes into the crank case you can monitor it immediately and see that.
The crankcase has orifices,
dipstick tube, fresh air vent (valve cover), oil pan return to valve cover (on S14 you can leave it alone), and the pcv valve (check valve) passage.
Seal them up and pressure test the crankcase as well (1-2psi MAX)
Do not use more than 1-2-3 psi inside the crankcase or it can damage an oil seal.
I doubt the issue is related to crankcase but its good to have each system separated and monitored for diagnostics.
air leaking from the cylinder, think about it:
1. it can get into the crank case
2. it can escape into cooling system
3. it can escape through intake or exhaust valves (listen in the intake and exhaust system)
4.... ??? Is there anywhere else it can go?
So to re-cap
if the cyl wall is cracked, it will go into coolant or crankcase systems.
If the valve is cracked or open it will go into exhaust or intake manifolds
If the piston is cracked (or rings are broken) it will go into crank case
no where else for it to go so... seal up each system... apply pressure...
To apply suction you may need a pump (electric or mechanical).
Alternatively you can run another engine to generate a vacuum and use that signal to apply to yours.
It sounds like either the coolant is being sucked into the cylinder through the wall under vacuum
or
sucked past the intake valve somehow (but you seem to have ruled this down or out)
|