is this a blown head gasket?
 

I have a 2004 2.4G and love her to bits. But she developed a sudden problem of coolant loss. Initially there was steam coming from behind the intake manifold. I used a product called T-seal. The steam stopped, but the coolant loss continues. There is no water in the engine oil. There is gas bubbling up in the radiator. Could this be something else other than a blown head gasket?

Appears to be a blown head gasket.

There is a test called a "Block Test" that tests for exhaust gases in the coolant.


The engine block is aluminum. Toyota had issues with the some of the head bolt hole threads in the block stripping out causing coolant leakage and a blown head gasket.

If you remove the head check for damaged head bolt threads in the block. If found there are well established DIY methods to repair the block in car or a shop can do the job.

What I don't understand is the fact that there is no water in the engine oil. Does this mean that the gasket leak is between the exhaust port and the coolant channel? Where is the water disappearing to?

A blown head gasket doesn't necessarily result in coolant in the oil pan.

This engine had a problem with coolant leaking out in back of the engine between head and block. Check for wet form insulation which is used to protect the plastic intake manifold..

Coolant could also leak into the combustion area and be evaporated.

If the head is cracked coolant can get into areas such as a spark plug tube.

Also check for coolant leaks in areas such as coolant hoses, radiator upper tank (check for cracks) and heater core (check for coolant on carpet under heater core)..