Radiator Cap on Expansion Tank

[Constant Mesh]

Just got a new Honda Civic and I noticed that the coolant pressure cap is on the plastic expansion tank rather than the radiator. There is no removable cap on the radiator.

A small hose just below the cap can dump excess coolant onto the ground.

This scheme is new to me.

There must be a volume of air above the liquid in the tank and below the pressure cap.

The plastic expansion tank appears rather robust and sturdy and I assume it's pressurized when the coolant is hot and expands.

 

[mcatrophy]

Wife's 2013 Audi A3 is the same. Quite common on modern car engines, I think.

 

[rbentnail]

Wife's 2013 Audi A3 is the same. Quite common on modern car engines, I think.

Yep, very common these days.

 

[mech 1 twa]

2016 Civic is the first Honda to use this system. Ford others have been using it for many years.

Did you get a Turbo? How do you like the CVT trans? They are pretty smooth a little lag then goes.

I always liked Turbo engines. Power and economy. Pull a hill and hardly push the pedal down or down shift.

 

[bigjohnsd]

This design makes it easier for air to find its way out of the system

 

[Geezer]

So, effectively, this system operates like a oversized radiator with space at the top for expansion, like my '63 Chevy had.

 

[bigjohnsd]

Yes