Tomorrow. Have a question and that’s that car from my neighbor cooks at the cooler over. Exhaust does not smoke. No oil in the water. No water in the oil. Spark plugs are dry. Engine jumps well however it is standing hot and water boils over. The workshop has taken off the lid at the cooler to see if water flows through. Because of water pump but water is pumped. The workshop says that the ZKD is defective. What do you think it might be due to defective thermostat because the hose from the kü ohler cold stays and the dare cooks over . Thanks for all the answers.