So I’ve got a slow coolant leak. Maybe topping up the reservoir an inch or so every 100 miles. Only seems to leak on longer journeys.
Can’t see any signs of leakage no puddles or wet patches nor any pink corroded areas. Pressure test seems to hold pressure. No sign of coolant in oil, exhaust smell in coolant tank or white smoke from exhaust.
What areas should I check next? What’s all the possible areas that coolant could leak internally?
Car is a3 8p 2.0 170 TDI CFGB engine
Many thanks in advance