UNKNOWN: Engine shakes and rumbles when going 35-45 miles per hour. Originally smooth when starting, now rumbles and shakes when started. Check engine light gs on and off. Engine kicks or jumps when accelerator is pushed… Not smooth, jerks very hard. Engine/starter/transmission issues. Available for inspection at dealership doing repair. Shakes and jerks going down the road. Feels like it’s going to shake apart. Currently at the dealership for repair and they diagnosed there is ‘Coolant entering into the cylinder’ Check engine light came on then went off. Did this about 3 times and is currently still on.