Damask_Rose
New member
- Location
- United Kingdom
- Car(s)
- Golf mk7 1.4 tsi
Replaced the heater matrix in my mark 7 1.4tsi yesterday and heating is now piping hot.
But now when I turn on the heating, the coolant temp drops, especially at idle.
So I graphed the temp using OBD11 on a 20 minute long drive. The drops below 90 are where I turn the heater on and the drop to the plateau at 60 is when I parked up with the heater on.
https://i.postimg.cc/tRNGgnHd/coolant-temp-chart-golfmk7-petrol-9-Feb2024.png
The car gets up to temp fairly quickly. It will stay at 90 unless I turn the heating on.
I have no loss of coolant and no leaks visible anywhere.
I have scanned the car and it has no error codes.
I had the thermostat replaced by a highly reputable garage in 2022 and the water pump replaced by the same garage about 6 months ago.
The problem only emerged after I replaced the heater matrix.
The heat coming out the vents is still very warm even when the temperature drops.
I believe that the temperature should stay at 90 once it gets there.
So I am a bit puzzled and stuck.
I would be extremely grateful for any help or advice.
But now when I turn on the heating, the coolant temp drops, especially at idle.
So I graphed the temp using OBD11 on a 20 minute long drive. The drops below 90 are where I turn the heater on and the drop to the plateau at 60 is when I parked up with the heater on.
https://i.postimg.cc/tRNGgnHd/coolant-temp-chart-golfmk7-petrol-9-Feb2024.png
The car gets up to temp fairly quickly. It will stay at 90 unless I turn the heating on.
I have no loss of coolant and no leaks visible anywhere.
I have scanned the car and it has no error codes.
I had the thermostat replaced by a highly reputable garage in 2022 and the water pump replaced by the same garage about 6 months ago.
The problem only emerged after I replaced the heater matrix.
The heat coming out the vents is still very warm even when the temperature drops.
I believe that the temperature should stay at 90 once it gets there.
So I am a bit puzzled and stuck.
I would be extremely grateful for any help or advice.
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