Rep Power: 0

I have a 1998 civic lx and I am having trouble bubbles in my radiator over flow. The pressure has gotten so high that it has blown the radiator. The pressure gets high enough to push out the coolant and then overheat. I have replaced the head gasket 2 thinking it was a blown head gasket. I am looking for a little help do I have a cracked block? would that cause this to happen? Could it be the valve stem seal needing to be replaced? basically at a loss, love this car it has 200,000 left in it for sure.

 
Rep Power: 174

When you replaced your gasket, did you do it yourself or did you go to a mechanic? If it was the latter and they were reputable, they should have checked it for cracks and warping before completing the job. You could do a combustion leak test (rent a kit at a parts store) to eliminate or confirm an exhaust leak.

 
Rep Power: 211

Possibilities:

1) Your radiator may be blocked up.
2) Water pump is failing but not completely failed enough to leak coolant.
3) Radiator fan not working properly