2017 1.4 TSI thermostat/water pump faulty?

[jakimpt]

Just dropping the coolant, and filling up again does not have the same possibility of trapping as much air as actually pulling of the thermostat housing/pump, and fitting an empty housing. These are very complicated cooling systems with multiple circuits, one way valves and pumps.

Of course a faulty new thermostat is 'possible' - but for me I would say you have more chance/risk of trapped air causing your problems than a faulty new stat.

Trapped air could cause your symptoms as well as a stat, as it can prevent the pump from properly pumping due to cavitation, restricting coolant flow!

A vacuum filling kit isn't expensive - if you don't have a compressor for the venturi, you could probably rig up some hand operated vacuum pump.

You can test your stat opening/closing with some hot water to determine if it is the new stat which is faulty.

Thanks for the insight.

Ok, I get it and it actually makes sense, as the housing is full of routings, two stats and the pump, which could cause some cavitation from the impeller.
Unfortunately I don't have a compressor neither a garage, so I would have to use a hand operated pump, if that's even possible?

Testing the stats means I would have to removed the housing again and open it, which could void the warranty in case I have to return the part.

Thanks

 

[SuperV8]

Thanks for the insight.

Ok, I get it and it actually makes sense, as the housing is full of routings, two stats and the pump, which could cause some cavitation from the impeller.
Unfortunately I don't have a compressor neither a garage, so I would have to use a hand operated pump, if that's even possible?

Testing the stats means I would have to removed the housing again and open it, which could void the warranty in case I have to return the part.

Thanks

There are DIY ways to vacuum fill your cooling system -

https://www.mg-rover.org/threads/how-to-vacuum-refill-coolant-system-using-a-pela-6000-and-a-rubber-bung.315806/?post_id=3297840&nested_view=1#post-3297840