Lately my car hasn't been warming up all the way, getting to around 168-171 normally but mainly around 168. So I thought since a thermostat is cheap I'll just replace it. Today I finally got around to changing it and it is still staying around the same temperature, and it got even lower when I coasted to down a long hill to 158. It eventually came back up but is this normal when outside temp is about 40 degrees or lower? Anything else I can check?

 

Could be a faulty engine coolant temp sensor. Replace it anyway, they are cheap, it's easy to access, and they get less accurate with age.

Or, the aftermarket t-stat you put in isn't closing soon enough or all the way. Lot of people have issues with the ones from the parts stores that aren't original.

 

Send me info for your tuner, I need a tune.
Even when it's like 30 degrees here I still reach operating temp of 180. Maybe your fan kicks on earlier than normal... Possibly a defective thermostat? Doubtful, but possible

 

The temperature sensor wouldn't be the little black one on the thermostat housing would it?

I think it's closing and opening fine, when I was bleeding it the car idled to 200 and the fans kicked in until 178 and stayed but when I drive it just won't get there.

 

no the temp sensor i'm talking about is the one on the front right of the head, right by the upper radiator hose.

 

My car is having the exact same problem except I just changed radiator ac Condensor and heat exchanger. My car will not get no higher then 170. It used to be 190. I'm not sure what to do.

 

Oh awesome, because I wasn't trying to go back down near the thermostat haha

 

I'm going to change the coolant temperature sensor and have my tune looked over and make sure the fans aren't always on low or something like that. If neither of them work I'm just going to assume it's because of the cooler weather and deal with it

 

https://www.cobaltss.net/forums/prob...ensors-318286/

 

Sounds just like what mines doing, I'll change that sensor. Thanks

 

Welcome.

 

Well I changed the ECT Sensor and it still won't get past 169 while driving. I'm probably going to try a new thermostat again or make sure the fans aren't always on low or something through the tune, I doubt that however though.

 

Whats the ambient temp for the coolant temps you guys are hitting? Also when are you checking your coolant temps? At idle, cruise, or stop & go traffic? At cruise my temps sit around 168-170F at 50-60f ambient. Stop & go traffic they'll easily start hitting 170-180f. At temps above 80f my cruise will hit about 175+ but my stop & go will get into the 190-200f. The only time I've ever seen temps of 180f or more is while cruising in 90f+ ambient.

 

My car has always ran between 176-181. Ambient temp 40f-80f.

Stop and go traffic will raise the temps up a bit due to less airflow, but once you get cruising again, they should drop back down.

When my ECT sensor started crapping out, my car wouldn't get past 163-165 degrees, no matter the ambient temp.

 

Isn't typically cooler engine the better? Like 160 all the time?

 

No.

 

If im correct, as your engine gets cooler its efficiency goes down.

 

What's the issue with running 10 - 20 degrees cooler than operating temp? As long as your oil is warm before you go wot. And heat won't blow as hot.