no compression

[benny f gsi,n it]

hey after just re-building my engine and went to fire her up today she has no compression, after inspection its all timed up right everything is good valves have just been re-ground head skimmed and all that by a engine builders. looking under the rocker cover i can see the hydrolic lifters are all hard when the engine is running (holding the valves open) so in turn getting no compression! cant work it out as i filled them full of oil before replacing them. any ideas?
Benny

[Adam]

You shouldn't have filled them with oil.
I usually just press them a few times in a tub of oil.

[Stuart]

let the oil drain (leave engine to stand) for a day. take the cam cover off and press down on all the lifters.
If that dosent work get the GM 8V cam removal tool and take the rocker/lifter out of each one and drain.

[benny f gsi,n it]

ok can you compress them while they in the head with the rockers on top?

[Stuart]

possibly

[benny f gsi,n it]

peice of wood and a hammer lightly ontop of the rocker?

[Adam]

Can you not move them by hand?

[benny f gsi,n it]

1 you can move the rocker up and down the rest are hard as rock

[benny f gsi,n it]

took the hydrolic lifters out and compressed all the oil out so they springy now but still have no compression dont know what it is didnt touch the bottom end as wasnt overhalled long ago head was built by engine builder but still no compression?????

[loggyboy]

double check timing, ignore any tipex marks and start from a fresh working from the bottom up.

[benny f gsi,n it]

yer we are 100% sure on timing, we now may think when the lifters were full (holding the valves open) it may have touched the top of the pistion and bent the valves but we didnt hear anything its a real mistery

[paddy138]

id say your timing is wrong and have bent exhaust valves.

[Adam]

Have you done a compression test?
Its not something like the spark plugs not sealing is it? Lol

[benny f gsi,n it]

yer put your finger over the sprak plug hole no compression at all

[Stuart]

very scientific...

[Adam]

very scientific...
FPMSL



Yeah, because your finger can hold 160+ Psi pressure lollol

[benny f gsi,n it]

well a way to see if theres any compression and theres none

[Adam]

Valve(s) stuck/bent open then.
Or cambelt timing out, you sure its not 180deg out?

[Welsh Dan]

Take thew head off.

[benny f gsi,n it]

yer we check the timing about 10 mins as we thought we were 180 out first of all, i think it mabe be head off and back to the engine builders :(