15/06/2026
A cautionary tale about mixing coolants!
We had a Giulietta QV in recently with a bit of a strange overheating issue. The car would maintain temp during normal use and idling, but would overheat when the customer drove up steep hills and used the turbo.
The car only had 48,000kms on it! The customer had just bought the car and was unfamiliar with its service history.
The first thing we spotted was the header tank being full of "green" coolant. It looked clean and relatively new, however the Giulietta came factory filled with "red" coolant.
Upon further investigation these pictures show the inside of the Thermostat. It had actually corroded in a slightly open position. It was allowing some coolant flow but not enough.
The colour of the coolant you use isn't the whole story, but it is certainly a good start. If the correct specification was used this problem was easily avoided.
