My friend's S-10 broke down today and won't start. I'm not sure of the year, but it's a late 90s-mid 2000s S-10 with a 2.2L engine. She described that she was driving on the interstate, and noticed the truck was losing power from the engine. She then started hearing a clunking sound from around the center of the firewall. She downshifted and the truck started slowing down more. Also the side tank of the radiator cracked spewing coolant. Now, when you turn the key to start the truck, the engine turns over with no odd sounds, but it doesn't start. It seems to spin as if it isn't getting compression on any cylinders.

I am truly clueless as to what the issue could be. I thought it could be that she threw a rod, but it doesn't make sense the engine's not making any clunking noises. The head gasket could have blown, but what are the odds that it blew on all 4 cylinders to the point that it won't start. There could have been some way valves got stuck or bent open, but again, all 4 cylinders?

Any ideas? We're going to start pulling the intake and head off tommorow since whatever's wrong will almost certainly involve pulling the head.