Only if it blows where ther is a coolant passage.

 

it won't always overheat with a blown head gasket...

I changed the temperature sending unit &theradiator cap, and it fixed the problem. Try that before you go and spend a bunch of money trying everything else.

 

look for a crack in the radiator, along the seam, and check to make sure your radiator isn't leaking.

 

We still need to find out what kind of temperature the coolant is getting.

 

make sure water and coolant is mixed properly also, water boils at a lower temp then coolant.. for the fans.. mine turn on maybe once in a blue moon when im in traffic and the temp needle on the gage hits in the middle... other then that it stays around a quarter way. could he have air in the system? maybe runing the car and finding the air bleed valve close to where the thermostat is and bleed the air out till it starts leaking the coolant out...? just some ideas

 

1. Check oil color. Chocolate cloudy milk is a coolant w/oil mix.
2. Break loose the drain plug slightly. Water is heavier than oil = Is the first to drip out of the threads.
3. If compression can push bubbles out of the radiator jackets, then water can walk back in under pressure when the engine is turned off.
4. Radi cap and a pressure test will show a fast pressure decline heading into a cylinder AND/OR out of the cap is test both ~ Since you did not mention any coolant on the ground, it is possible to enter the engine or over flow tank.
5. Engine leak down with the radiator cap off will pin point which bank the head is.
6. Say it is a blown head gasket? Surface check the heads for warp. Since one head is possibly off for a leak, it would be wise to do the whole job, or when will the other one blow is why sit on a time bomb.

 

isn't there a hose that goes to the resevoir? mine went under the battery and was a lil crimped and blocked it up somewhat. its very normal for antifreeze to flow back and forth thru there. if its blocked it would do what you describe because there is nowhere for it to go.