SEAT LEON
Q I’m having trouble with the interior heaters in my 2014 SEAT Leon 1.6 TDI. With the dial on fully hot, on one day they are hot and on another they are lukewarm or cold. Similarly, sometimes the right vent will blow out warm air and the left vent will be cool.
I have tried two new coolant bottle caps, with no joy. A couple of times I have had to top up the coolant slightly because the warning light came on saying low water – it was slightly damp under the coolant bottle, hence why I tried a new cap – but the level hasn’t gone down in more than a month. Would it be worth trying a new coolant bottle, say if the threads were worn where the cap screws on and letting pressure out?
Looking under the car there are two auxiliary water pumps – one in front of the coolant radiator and the other behind the engine, which seems to plumbed to the EGR cooler. Would these have anything to do with supplying/pumping water to the heater matrix? Or do you have any other ideas?
A The heater unit in your Leon uses servo motors to operate the air flaps to direct air either through or round the heater matrix. The left and right sides of the heater unit have different flaps and this could cause one vent to blow warm and the other cold. I suspect the problem lies within the heater unit, not due to pressure loss in the main cooling system. As you do not mention any overheating problems with
