No coolant temp
Premium Member
Joined: 03-12-2017
Posts: 1,250
From: Phoenix
When the ---F reading appeared on mine it was under warranty so dealer fixed it for free. The issue is with the before and after temps. If the variance is out of spec the ECU lets you know but won't tell you what the issue is.
Senior Member
Joined: 09-16-2013
Posts: 1,408
From: Tampa, Florida
I think its if the car doesn't get up to temperature quick enough, the ECU determines it cannot properly monitor temperature, and puts itself into safety mode by disabling AC and turning cooling fans on high to avoid possible overheating, since it doesn't know what the actual engine temp is.
Thread Starter
Member
Joined: 06-26-2017
Posts: 83
From: Los Angeles
Damn! That's a lot cheaper! I should have checked it there. Lesson learned.
Glad it's working for you, that old one was certainly a problem. $81 OUCH!! I think I'm gonna order one now, just to have it. 20% off coupon right now on Amazon, comes to about $32, w/free shipping.
https://www.amazon.com/ACDelco-131-1...ct_top?ie=UTF8
https://www.amazon.com/ACDelco-131-1...ct_top?ie=UTF8
Thread Starter
Member
Joined: 06-26-2017
Posts: 83
From: Los Angeles
Actually the GM one also has a rubber gasket on the valve but it's a lot smaller and seems to be molded onto it. You can see it in the second to last picture if you zoom in.
Some people are stubborn (me) and need to learn a lesson. ;-)
The thermostat can cause the engine running cooler if its stuck open. You are correct about it's job but it's not an on/off valve. It gradually opens and closes adjusting the coolant flow. It that's obstructed the symphony falls apart. Now that I have the new one the engine seems to run 5-10F cooler. It used to swing between 190 and 200F. Now it's around 183F +/- a few degrees depending on speed. Probably because it can move freely while the old one was sticking.
Regardless you were right about the thermostat being the culprit. So thanks for the help!
Some people are stubborn (me) and need to learn a lesson. ;-)
The thermostat can cause the engine running cooler if its stuck open. You are correct about it's job but it's not an on/off valve. It gradually opens and closes adjusting the coolant flow. It that's obstructed the symphony falls apart. Now that I have the new one the engine seems to run 5-10F cooler. It used to swing between 190 and 200F. Now it's around 183F +/- a few degrees depending on speed. Probably because it can move freely while the old one was sticking.
Regardless you were right about the thermostat being the culprit. So thanks for the help!
That is the aforementioned inner rubber gasket that always fails on the wrong t-stat!
The 131-158 is metal to metal, no point of failure.
I wish people would start listening to us "old farts".
The t-stat has nothing to do with the motor running cooler; as I have tried to make clear it's job is to keep the temp ABOVE 180F and to get it there QUICKLY from a cold start.
The 131-158 is metal to metal, no point of failure.
I wish people would start listening to us "old farts".
The t-stat has nothing to do with the motor running cooler; as I have tried to make clear it's job is to keep the temp ABOVE 180F and to get it there QUICKLY from a cold start.
Thread Starter
Member
Joined: 06-26-2017
Posts: 83
From: Los Angeles
I know, I know. But having no code threw me off. Even if it was something else I would have changed the thermostat for good measure. I don't trust the PO.
I changed as much of the coolant as I could. From the 2+ gallons about 1.5 came out. And I flushed the radiator.
I changed as much of the coolant as I could. From the 2+ gallons about 1.5 came out. And I flushed the radiator.
Thread Starter
Member
Joined: 06-26-2017
Posts: 83
From: Los Angeles
This is most likely what I had with the thermostat sticking. It also explains why I didn't have a code.
Thread Starter
Member
Joined: 06-26-2017
Posts: 83
From: Los Angeles
I think its if the car doesn't get up to temperature quick enough, the ECU determines it cannot properly monitor temperature, and puts itself into safety mode by disabling AC and turning cooling fans on high to avoid possible overheating, since it doesn't know what the actual engine temp is.
Joined: 09-30-2018
Posts: 7
From: OK
I am having the same issue. My temp has always displayed up until this last weekend. I haven't tested to see if the A/C is working as the outside temperature has been nice. I did see that it was working the other day when I left work about 5pm local time. It may be the sensor going out, but I haven't tried replacing anything yet. I wanted to see if others were having the same issue.