Good afternoon everyone.

I picked up a 2010 base cooper that had a broken timing chain. I pulled the head because I wasn't getting good readings from the cylinder leak down test. I have the head on the bench and I'm going through all the valves to determine if I have any bent. What I have found so far is that they have a ton of carbon built up on the valves and seats.
I have a question about my intake valve opening that I'm hoping someone on here can answer.
when I rotate the intake cam over to check the two valve openings on each cylinder. One intake valve will open all the way while the other just barely cracks open.
it does this on each cylinder. It makes me think its normal since all 4 cylinders open the same . Is this normal for the vanos system or do I have bent valves? Both intake valves on each cylinder are supposed to be identical and I can see any difference in the cam lobes. All the intake valves seem to seal good but will need the carbon cleaned to get a perfect seal. I cant see ant warpage on the stems
any help would be greatly appreciated.
BTW, I have a Bentley manual but a friend borrowed it and I'm waiting for them to return it.

 

N12/N14 still have a hydraulic lifter at one end of the roller cam rocker (other end is on valve)...likely one lifter is bleeding out or one is stuck open (on each cylinder). Try pushing all the lifters all the way down by hand before turning the cam...see what you get!!

 

I rolled the intake cam over again and tried pushing on the lifters. They seem well planted. I did notice tho that when I got the valve to open a lil , it slowly bled down and back closed. I deal with a lot of hydraulic lifters and valve trains in Harleys and domestic cars but ive got a learning curve on these. What confuses me is that it does the same thing on each cylinder. Same valve . The first will barley open but the second one will open all the way up and doesn't bleed down at all. All the intake valves are sealing and pass the pressure/leak down test.