2019 Forester - Thermo Control Valve failure

[forester2002s]

Not my car, not my problem (yet).  But here's an interesting article about Thermo Control Valves (TCV) on newer Subarus.

This link, from the Canadian newspaper The Globe and Mail, is behind a paywall: Costly repairs because of new thermostats will be a growing complaint for drivers . It may not let you in; so I've copied and pasted the text below:

LOU'S GARAGE: Thermostats aren’t what they used to be. Gone are the days of the General Motors drop-in style thermostat, where you easily took off a coolant cap, reached down, grabbed a handle, pulled out and replaced an $8 thermostat in 30 seconds.

Now, we have complex units referred to as coolant or thermo modules, thermo control valves (TCV) and in many cases, the common contemporary thermostat is only serviceable as a complete unit incorporating a large plastic housing.

Owners of European vehicles have tolerated these costly units for at least a decade, but the rest of the automotive world is now becoming painfully aware of this newer tech. These units offer finer temperature control using rotary slide valves that direct coolant flow precisely around the engine and are faster at responding to engine load change. The engine will reach ideal operating temperature 50 per cent faster and keep it there over a wider variety of conditions. Whereas a thermostat is a straightforward valve that merely regulates coolant flow, a TCV can be thought of as a mixing valve. The thermostat is now the coolant gate keeper and the TCV is the director.

Case in point is a 2019 Subaru Forester in the shop this week with a Malfunction Indicator Light (MIL) on, no heat inside the cabin and an engine that won’t easily reach operating temperature. This vehicle has a traditional thermostat, but it also has a TCV that has recently failed, leaving this vehicle with no heat. The vehicle has 70,000 kilometres, putting it just outside of its warranty period, thereby passing this costly repair onto a shocked owner. You would be too if you had just received a quote for a $882 part plus a couple hours of labour.

Why do we need these units when a simple thermostat has done the job previously with very little fanfare? Well, ever-tightening fuel economy regulations have all auto manufacturers scrambling, looking to squeeze every morsel of mileage out of a litre of fuel. This complicated part does exactly that by elevating fuel economy and reducing CO2 emissions approximately 4 per cent. This may not seem like a lot, but manufacturers have no choice in the matter.

This means you have no choice either. The Subaru owner mentioned above is heading in again next week to his local dealer trying to find some financial relief for this repair. In my opinion, 70,000 kilometres seems awful early for such a costly repair to be sprung on an owner, especially when you factor in that up until last week, he had never even heard of a thermo control valve. I suspect this will be a common complaint in years to come for a lot of aging vehicles.