ghood,

It all sounds very suspicious.

Usually an oil leak is the rear main seal and/or the turbo oil return line.

A "broken" head usually means that the timing belt has failed and the valves and pistons have shared the same space at the same time. This does not lead to a good outcome for an interference engine.

I don't see how a split turbo hose (4" diameter--to the intercooler?) would do anything except cause loss of boost and make the ECU crazy. Maybe the fan could be damaged if pieces flew into it. The "popping" sound may have been a tiny air leak prior to total failure of the hose.

If you mean the coolant line (4" length?), then the turbo might sieze and fail--shouldn't trash the engine.

Water under the engine could mean that the lower radiator hose burst. Again, if you pulled over immediately and stopped the engine, there should not be permanent damage.

Find an indy mechanic or another dealer to check the car.

Then, contact you attorney general's consumer fraud division. It sounds like you may have to confront the dealership on its mechanic's diagnosis and repair of your car.

Bryan