I have a 2004 CRV. I have no compression in one cylinder (2nd left to right). The rest have over 165. I checked if block have some cracks and it doesn't. I checked if head seal/gasket have damage and it doesn't. I don't think its the cylinder, in that case the other cylinders would have similar wear/damage. I guess its the valves. What you think?

 

At this point I don/t know if take the engine to fix it or replace it.

 

This is the CRX/EF Civic section, so first suggestion would be to post this inquiry in the correct subforum for your vehicle.

To save you some time though, you'll probably be directed to do a leak-down test on the bad cylinder. This should help determine where you're losing compression. Once that's done the CR-V guys hopefully can help you out. Good luck.

 

This^

Also, did the timing belt slip or snap? If so, a bent valve is likely.

 

Have any vehicle history? What happened before all this? Did it run before you took it apart? If you already took everything apart - sounds like it, since you were able to check the head gasket for leaks and the block for cracks - I would rebuild the head with new valves and stem seals (at least on the faulty cylinder). Double check your timing, tension etc., because that seems most likely what failed. You should have done a more thorough compression test from the start to eliminate the rings and help identify which valve failed.

K24 might have a chain but yea that sounds likely.

 

Given the timing chain of the K24a1, maybe a burnt exhaust valve is more likely.