[Florenciosc]

Are you running your engine with anti-freeze?, because on vehicles that had run with water, and its rusty, rust tends to eat the little blades on the water pump, and if you check your car at idle it assumes to be working right, but when it works under pressure it tends to fail, because these blades are either worn out or doesnt exist anymore, also if you dont take care of this your engine head can get damaged too.