Zero compression after new head

[Lucas03es]

So my buddy lost compression in his #1 cylinder and decided to buy a different head for it. Once he got it installed he said all four cylinders have zero compression on the compression tester he got from autozone (we will be testing it with a different gauge). Does anybody have some ideas what it could be?

 

[Dewayne Waldron]

Your HLA's are defenitely the problem. Listen to what sbrjoe and colt4g63 are saying. I know this from experience.

 

[1fast97gsx]

I disagree with all these statements .... the car was mechanically timed wrong or the head is damaged. If it was lifters you would have low compression, but not NO compression. Are you sure intake and exhaust cams werent accidentally switched? Did he maybe not follow timing procedure 100%? I would almost bet money on timing.

 

[Dewayne Waldron]

I disagree with all these statements .... the car was mechanically timed wrong or the head is damaged. If it was lifters you would have low compression, but not NO compression. Are you sure intake and exhaust cams werent accidentally switched? Did he maybe not follow timing procedure 100%? I would almost bet money on timing.

I would take your money too. I had the same problem as the op and everyone else on this post with 0 compression across. Bled the lifters and gained back all compression. Flat or overfilled HLA's will cause this. I've seen it a million times. It's NOT the valves or timing.

 

[Lucas03es]

Well he couldn't figure out what it was in time before he has to go home and leave the car to get parted out and salvage whatver he can off of it for sell. He just doesn't want to deal with it anymore, and with two different sets of lifters the problem still occurred. Thanks for the help guys

 

[bling5tatus]

How do "flat" hla's cause this issue if they don't allow the valve to open up when the cam lobe comes around?

I tested mine yesterday w/ compressed air. It blew air from the pcv hose which means intake valves leaked..... so i took the rockers off those two valves and tested again.... it tested good, held pressure. I then bled all the HLA's and reinstalled them. When I started the motor #3 had compression again and wasn't a miss. After driving it to work however, the lifters have pumped up but #3 seems to be missing again.

What would cause that to happen? It seems to me that the HLA's pumped up enough to somehow hold the valve open, how is that even possible? Am I wrong in my theory or is there another explanation?

 

[DeadlyAKrunna47]

One time a long time ago on this galant i was working on, i installed a head that was rebuilt, Looked super fresh! Once i was finished, it did run for 5 seconds. Then it was damn near 0psi compression in all 4!

The issue was there was so much metal shavings in the head from the machining that it clogged the lifters and left them open.

 

[1990TSIAWDTALON]

One time a long time ago on this galant i was working on, i installed a head that was rebuilt, Looked super fresh! Once i was finished, it did run for 5 seconds. Then it was damn near 0psi compression in all 4!

The issue was there was so much metal shavings in the head from the machining that it clogged the lifters and left them open.

I ALMOST had a situation like that with my motor so I HIGHLY suggest after machining a head to at least take it to the compressed air and tip it up and blow all the water coolant passages and oil passages out as that is where the shavings like to hide and my head had a BUNCH in it. I repeated that process at least 4-5 times and finally got all of the crap out of it. Boy am I glad I did that. I didn't notice it until I was test fitting the head on the block and noticed some curly aluminum on the block after I took the head back off. Just words to the wise and good that you pointed that out DeadlyAKrunna47!

 

[DeadlyAKrunna47]

The lifters were full of metal shavings. that kept the valve open!

 

[Deve]

I rebuilt my head recently and was told to make certain that all lifters were empty and squishy when I re-assembled the head or I would end up bending the valves. Not sure what was done here but going forward mine went together and worked. The head needs to be leak tested and the cam gears need to be aligned properly when re-assembled. They will tick until they are full but that is better than no compression.