I have shared my vehicle specifications below.
DS / DS 7 CROSSBACK 1.6 PURETECH 225 / 2018 Performance Line
Construction Type: SUV
Cylinders: 4
Cylinders (ccm): 1598
Cylinders (liter): 160
Fuel Type: Petrol
Fuel Type Process: Direct Injection
Impulsion Type: Front-Wheel Drive
Motor Type: Petrol Engine
Valves: 4
I’m the second owner of my DS7. At 108,335 km, I decided to do the first maintenance, which included replacing the alternator belt (V-belt) and the original orange coolant. I had the work done at an authorized DS service center. The service told me that newer DS models now use blue coolant instead of orange, and I agreed to the change.
About 3–4 months after the coolant replacement, I noticed that the coolant level had dropped, and when I checked the expansion tank on a cold engine, the level was below the minimum mark—it even looked completely empty.
Despite that, the temperature gauge always stayed at 90°C, the AC system worked perfectly, and I didn’t experience any performance issues or warnings.
I contacted the DS service and brought the car in for inspection. When they opened the coolant cap, the level suddenly rose back up between the MIN and MAX marks. They explained that these cars operate under pressure, so this was supposedly normal and that I could continue driving like that.
When I asked how the coolant was filled, they told me they simply poured it directly through the expansion cap.
After doing some research online, I found that modern cars require specific procedures before refilling the coolant, such as vacuum filling and air bleeding (degassing).
I also came across some discussions mentioning that when changing the timing belt, the thermostat is often recommended to be replaced as well, although many mechanics skip it.
A few days after my second visit to the service, they called me again. They said that another customer who came after me had their coolant warning light come on, and upon inspection, the cylinder head gasket was found to be blown, requiring a complete cylinder head replacement.
This worried me, so I had my car checked once more. After about 5–10 minutes of inspection, they told me there was no warning or issue, just that they added a bit more coolant and advised me to “top it up if it goes down again.”
Honestly, this situation left me doubtful.
It doesn’t seem normal for the coolant level to drop continuously. I’m not sure if the air bleeding (degassing) process was done properly or if the system wasn’t fully drained and refilled correctly.
If anyone here has experienced something similar or has technical knowledge about this process, I’d really appreciate hearing your opinions and experiences.
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