Mahindra smoking

[tpsball]

Hello, I have a 15 year old Mahindra 2810, just started smoking real bad, kinda blue smoke, smells like diesel fuel. I cleaned out the fuel filter that was terrible and put fresh Kero in. I also noticed the Coolant tank was at low level so I filled it and it started to blow a stream pf coolant out the top and the upper hose was rock hard. it has normal power. im hoping it was bad fuel that was causing the smoking but now with the pressure in the coolant leads me to think head gasket?? any suggestions? Thanks