audi 1.8t cylinder head

[47silver]

hello:
i intalled a remanufactured cylinder head on our 1.8t audi 20 valve.
I did a leak down test after i installed the cylinder head.
number 1,2 and 4 were perfect.
the forward intake valve on #3 leaks, but moves in unison with the other 2 valves.
All seems to be ok but the valve is not seating.
Question:
if i start the car do you think the valve will seat? it is not bent as far as i can tell
any experiences with this type of thing would be appreciated, i hate to tear it back apart and get new bolts etc.

[Jared at Pelican Parts]

What are the numbers?

[fanaudical]

You might dribble some Marvel Mystery Oil into that intake port and then crank the car with the starter and spark-plug in to see if compression alone will seat the valve. That should seal reasonably well right after reman.

[47silver]

1,2 and 4 were under 15%.
#3 was 35%....and i could hear the air leaking at the valve.. When i inserted a rubber stopper in that intake valve channel and the reading went to the same amount as 1,2 and 4.

I pumped air high pressure air into the cylinder but i think it would need combustion to seal if that is the problem.

Damn, was going really good too.
Advice: change timing belt and water pump if you ever buy a use audi even if they tell you it was changed "recently".

[asphaltgambler]

You have a valve issue with your "rebuilt" head. Plan on removing it to see why the valve is not seating correctly

[Jared at Pelican Parts]

Agreed. you need to pull the head and figure out why the valve isnt seating. The valve may not have been lapped in correctly.

[47silver]

i concur, may as well pull it off and see what is wrong with it.

[1990C4S]

Will it be easier to yank after you drive it? No. Do it now.

[47silver]

We pulled the head off tonight.
With the intake valves on #3 fully closed we shined a bright light in the intake port and darkened the room. We could see light around the edges of the valve and seat on the forward #3 intake with it fully closed.

We opened the valve and cleaned the valve and seat with an ear swab soaked with pb blaster.
The swab was not very dirty and we did not see any hard materials that could keep the valve open on the swab. Not to say it did not fall off when i cleaned it as i was a bit discouraged that the valve was leaking enough to see light when closed.
However, when we then rotated the cams and the valves snapped shut. and then shined the light, it was sealed tight.
We then injected the valve port with wd40 and it has retained it for 3 hours without leaking a drop..
Fixed, and with luck will be back together in a couple of days.

We would have had it together tonight but we did not want to reuse the head bolts or cylinder head gasket.
Again thanks for all of your input, i think that the open valve may have backfired and caused intake damage so all in all i am glad we took it back apart.

[fastfredracing]

The valve lifters had not bleed off all the way just yet. this happens to me frequently when doing vw heads. Usually , just leaving the offending valve fully open for 20 minutes or so will do the trick ( this uses max valve spring pressure ) . The last 3 series BMW I did , took over 24 hours before I had all the valves closed, and could install the head. Glad you figured it out.