Last time I checked golems can die from various things like mobs, fire, drowning, blocks, lightning and etc. Make sure they are in safe surroundings as well. If that is not the case then it might be what Bruny said.
I have read this as u told me and I really liked it.Great way to have a loads of power,only bad thing is that it needs a lot of ender pearls but still I'm impressed.
Good work