Hey everyone, with winter fast approaching i was hoping to get some insight into an issue ive had previous winters where my car wont reach a high enough operating temp when its -10c or lower. After a couple days of winter driving ill get a check light and a code P0128 i believe. I also get no heat unless i tirn the heat off and let it warm up then i get about 5 minutes worth of warm air and it cools right down. I was thinking it may be my thermostat stuck open but im not 100% sure of it. If anyone has any suggestions id greatly appreciate any and all help

 

definitely the tstat

 

Here in Manitoba my car won't heat for at least 30 mins of highway driving when it's real cold.

Try covering part of the rad with cardboard.

But also check your tstat.

 

Definitely start with the thermostat. I would be surprised if it's anything else.