installed new head, weird compression numbers

[turbo98eclipse]

Hey I was having issues with compression previously (cyl2) and it lead to bent valves. I replaced the head and its now fixed. Compression is (1-4) 170 170 170 140 .... I know 140 is still ok, but im confused why one is at 140. (Added a cap of oil and there was no change)

When I got the head I did a fluid bench test on it. I got all the lobes off the valves and everything held, until I got to #4. There was a very small amout of light showing thru the valve seat and water wouldn't hold too well. I did some reading and saw you were supposed to take the cams and everything out to do the fluid test properly (which I didnt) so I figured it may have just been a lash adjuster filled with oil keeping it partially opened, so I ignored it. Install went well and engine runs great.

Is this something I should be concerned about? I figured if the valve was open at ALL it wouldnt be at 140 after I stopped cranking, got out the car, and walked around to check the gauge. Im assuming it would have bled almost all the way down

 

[donniekak]

Probably needs a valve job. You may be able to get by with hand lapping the valves though. Why put a leaking head on the car?

 

[BogusSVO]

If the HLA was pumped up and holding the valve of the seat, you would see light all the way around the valve, not just part.

The valves can bend from just the weight of the head on an open valve.

 

[turbo98eclipse]

If the HLA was pumped up and holding the valve of the seat, you would see light all the way around the valve, not just part.

The valves can bend from just the weight of the head on an open valve.

Im 90% sure that the light could be seen all the way around, its just the angle I took the picture at that makes it hard to see. The guy I got it from said that It was recently rebuilt (which I think it true because I found some assembly lube inside it). It was only that 1 valve out of all of them... pretty sure it was intake valve #1

EDIT:: this is another pic I had taken from the outside of it. Its the top valve. If you look close, you can see how much its open. So judging from this pic, the valve was open all the way around

2nd EDIT:: dont worry about the bottom valve in that pic: it was open because I didnt have that sides cam rotated to have that valve completely closed.

 

[turbo98eclipse]

Well I did a leakdown test today and every cylinder was at 20-25% according to the cheap HF leakdown tester I got. I didnt hear any air in the intake or exhaust, even on the valve that I thought may have been bad.