Bad city MPG
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,089
Likes: 819
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,089
Likes: 819
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
Did notice the digital coolant temp is acting weird. Got car out of the garage, turned it off to close garage door. Before I turned it off, coolant temp read 136. Start it back up like two minutes later, and it reads 99. That can't be right. Then, on the drive, it stayed at 103 to 109 for like two miles, then went straight to 190. Not throwing a code.
Burning Brakes
Joined: Mar 2005
Posts: 1,082
Likes: 115
From: Richmond Hill Ontario
I assume these readings are from the digital LCD. How do they compare to the analog gauge?
The ECM uses the digital reading (CTS on water pump) for fueling calibrations.. that could be causing your problem.
The ECM uses the digital reading (CTS on water pump) for fueling calibrations.. that could be causing your problem.
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,089
Likes: 819
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
Yes, from the digital LCD. Analog gauge is always higher. But I did connect my scan tool when I got back home, and it told me 203 degrees. Same as what the LCD said. So I guess the sensor is going bad. Bought the coolant sensor at the Chevy dealer, so if its bd, still under warranty.
