The head gaskets went bad slowly first with a gallon of antifreeze every 2 weeks and then the reservoir started to run dry sooner. i took it to the mechanic and he said the head gaskets went on the motor and mixed with the oil and became a milky mud in turn made the motor start to tap and make noises, he suggested another motor due to the oil getting thinned out would have worn the internal motor parts down and would blow the motor anyway so replace it he said. at 98,000.
The venture is comfortable and roomy{extended version} and motored along great but the motor just went bad without any signs. overall we were happy, but now unable to afford to replace the motor.
You claim the engine died without warning, but the very fact that the engine was using as much antifreeze as you say is all the warning you should have needed. In the future do yourself a favor and have whatever vehicle you own at the time checked out IMMEDIATELY if it using that much antifreeze, it makes for a horrible lubricant!