v8killaz

well heres the story
b16 em1. he said it happened over time got worse. sounds like a subaru and he said he had very hard starts sometimes
buddy comes to me saying his valves are bent. he said he just checked them with the shop and they did a leak down. so do a leak down to confirm and the numbers are so

10% in cylinder 1
40% in 2
30% in 3
40% in 4

compression test as
210psi in 1
130psi in 2
40psi in 3
90psi in 4

40 percent meaning the air was just blowing out 100% from the tester out through the cylinder. I could hear it in the exhaust valves clearly so i agreed the valves were bent or seals were bad.

so while i took everything out i noticed the timing belt was loose. enough where it could skip teeth like but the bolt on the tensioner was tight

heres the problem when i first checked the belt it was perfect at tdc for piston number 1
and then when i rotated it it got loose and loose until it had alot of slack at cylinder 3
and the cam gears could move with a wrench about a cm


fast forward now i take the head off anyways because new cams and head gasket. as i take the head off i see no signs of bent valves and cylinder look fresh and pistons are good. the head gasket is good, no water oil mixing or anything like that.
i took the valves out and they are perfect the guides are good and the seal is good.

my question is can the valves still be bent, all i did was check them with my eyes and rolled them. or could a loose timing belt cause that. because I would think since the timing is good at tdc for 1 it would be good for cylinder 4 also.

Dale_K

I remember reading in one of the hot rod magazines where they were checking valves for leaks and they turned the head upside down on a bench and poured a little gas in each combustion chamber (be carefull). If some are holding and others leaking you should see the gas disappear where the bent valves are. But if you heard the air leak sound there must be a problem.

canadaek

if it move's when you turn it by hand just image how bad it slips when you try and start it .
try puting some vasaline on the valves and then fill the combution chamber with water and watch for leaks (leave the spark plug in also

Ci-v-iC

Yes, loose timing belt could have caused your problems -my guess is it the tensioner was the culprit- it's wise to replace them while installing a new TB.

v8killaz

the valves are sealed and i tested them with some light oil and it didnt leak through but of course that doesn't mean their straight but should cross them out as the cause of the low compression issue.

Ive decided the best thing to do right now is but a cheap headgasket or reuse the stock one tq down the head bolts and then redo the timing and check to see if the issue is resolved. probably what i should have done in the beginning but me being in a rush. I need the car out the garage and dont want to redo everything.
hate parking my car outside


one question i dont need the manifold on the car to check for compression right
i can just slap the head on bare with the cams and upper assembly and should be good

canadaek

ya you can check without the intake or exhaust on but use a new gasket never reuse a headgasket

v8killaz

i just checked them and reused the old hg and they are the same numbers with the timing dead on
so we will be giving the head to the shop to pressure test it

tuck1crx

weird... yea get it pressured tested.. im interested to see what the problem is. stock pistons and cams?

v8killaz

yeah stock motor
i wish the head comes back as bad. so it can be fixed.
but i checked most of the valves and to my eye they were straight and in great condition no discoloration or anything.