Jun 28, 2026
2
1
Please help!

We have a Seat Leon 2.0 TDI 184bhp, 65 k miles on the clock and it is losing coolant on 30-50 mile journeys but no obvious signs of coolant loss and no overheating.

Originally it was losing its whole coolant tank of coolant. We have gone through all the common issues, it has been pressure tested and emissions tested with no issues and replaced coolant tank cap. We have tested the heater matrix and both sides hot - have felt both pipes going in and out of the matrix and both get very hot, the silica bag is also in tact (we have removed this now) and there was no wet floor in the passenger side however the drivers side is slightly less hot than the passenger side but still gets hot.

We have since taken it a German specialist garage and said it wouldn’t be the heater matrix with both sides still getting hot and they suspected inlet charge cooler, to which they did find traces of coolant and so we have replaced this. However since we have had the car back, the coolant is still dropping from the max to the min so less than it was but still dropping. I know some air might be in the system from this replacement but it has been topped up 10 times now when it is only suggested this should be 2-3 times. Each time it is only between the min and max.

Really unsure what to do now, any help is greatly appreciated!!
 
Last edited:
^^^^ Reduces the risk / likelihood but doesn't eliminate it.

I had the water pump changed on one of my Ateca VZs as the seal was leaking; under warranty and had started losing coolant with >10k miles on the clock.

Conversely, on a 2.0L TDI Yeti the water pump was changed with cambelt at c. 60k miles, as there were early signs of a leak.

Guy

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