Change Coolant Control Valve? ...Moving to Subzero Temps

2004 Prius with 250K miles and thousands of ilde hours (Prius Camper).

P1121 and Pending P1116, Living in Coastal Southeast now Heater works very well

Have 3month or more work assignment in NW Iowa with subzero Temps

Should I change the engine coolant control valve and the sensor it comes with because the subzero temps

or can I let it ride like I have been doing?

I believe I understand it has something to do with saving hot coolant to warm car on restart but could have that wrong or not exact.

Is it critical to get that changed because of the subzero temps?

Both coolants are not due to be changed for a while according to the manual.

I'm just trying to nurse this Prius along until I get another but need it to start in the sub zero temps.

Battery is in good shape according to Dr Prius and getting 43 mpg 70mph

There are other expensive repairs like AC system but won't need where I'm going

Not attached to the car as once was and will get a newer used Prius or RV later this year

Need to make this decision in a day or so. Thanks in advance

 

Thanks for the quick reply. Yes cabin is very good now but could change with subzero temps.

Does it also have effect in making sure engine starts with warmed coolant especially in subzero temps?

Cabin heat not working like it is now is enough to pay the $400 for hybrid mechanic to do it right.

He said it would test coolants too to be sure they can handle subzero. Thanks

 

Thanks for the reply. I don't notice any noisy startups or noisy shut downs in mine yet of course that could change in Iowa. Here the lowest temp so far is 28 but Feb gets colder.

I assume you have the P1121 and possibly P1116. The light comes and goes on mine. Fortunetly for inspection it was off. I may hear some pump running for a while which may be filling or trying to fill the canister.

This is a tough little car. I may go ahead and get it done and get a look over for the trip having a good hybrid mechanic here that talks to you (ex-Toyota)

Need to get some warm boots so I don't get frostbite on my toes and waterproof. Have winter gear for all the rest that I would be sweating in here . Little dog will have to stay inside Jan and Feb.

Small friendly town in Spencer IA. Thanks

 

Just got engine coolant valve replaced and noticed a boost in my mpg at 55 degrees F here from 39-40 mpg to close to 47mpg regular in city traffic (from cold start) which my 2004 Prius hasn't seen in a while. That's from the display. I'll have to do more extended tests when I have time and post to thread.