Check Coolant Level Issue and Rough Idle With Cold Starts
Thread Starter
Melting Slicks
Joined: Jul 2016
Posts: 2,456
Likes: 495
From: Clearwater, Florida
Check Coolant Level Issue and Rough Idle With Cold Starts
Hello all!
I've been experiencing an issue where my Z06 will idle a bit rough shortly after starting the car when it's cold. The RPMs will dip down below 500 at times and the coolant temperature will fluctuate and change temperatures immediately (usually 30+ degree instant changes). Eventually, this will cause the car to throw a "Check Coolant Level" message. On occasion, the RPMs would dip so low that it seems to car will stall, but it doesn't.
The coolant level is fine. It previously threw a P0118 code which is related to the Engine Coolant Temp sensor. I've replaced the sensor and the pigtail harness, but the issue persists.
When the car is fully warmed up, this issue completely disappears. The coolant temp gauge is normal and I don't get any Check Coolant Level messages.
Here is a video after starting it this morning:
https://photos.app.goo.gl/VX5Kn6WdA7xH7VqTA
Could a faulty thermostat cause these issues? I wasn't sure if a thermostat issue would display instant temperature changes or 30+ degrees. I'm not sure where else to check. I would greatly appreciate any help!
I've been experiencing an issue where my Z06 will idle a bit rough shortly after starting the car when it's cold. The RPMs will dip down below 500 at times and the coolant temperature will fluctuate and change temperatures immediately (usually 30+ degree instant changes). Eventually, this will cause the car to throw a "Check Coolant Level" message. On occasion, the RPMs would dip so low that it seems to car will stall, but it doesn't.
The coolant level is fine. It previously threw a P0118 code which is related to the Engine Coolant Temp sensor. I've replaced the sensor and the pigtail harness, but the issue persists.
When the car is fully warmed up, this issue completely disappears. The coolant temp gauge is normal and I don't get any Check Coolant Level messages.
Here is a video after starting it this morning:
https://photos.app.goo.gl/VX5Kn6WdA7xH7VqTA
Could a faulty thermostat cause these issues? I wasn't sure if a thermostat issue would display instant temperature changes or 30+ degrees. I'm not sure where else to check. I would greatly appreciate any help!
Last edited by Frankie15; Today at 11:47 AM.
Thread Starter
Melting Slicks
Joined: Jul 2016
Posts: 2,456
Likes: 495
From: Clearwater, Florida
Melting Slicks
Joined: Nov 2009
Posts: 3,303
Likes: 1,156
From: Klein TX
2023 C6 of the Year Finalist - Unmodified
2022 C6 of the Year Finalist - Unmodified
Were the new sensor and pigtail GM parts or aftermarket? Lots of bad luck lately w aftermarket electrical stuff.
Thread Starter
Melting Slicks
Joined: Jul 2016
Posts: 2,456
Likes: 495
From: Clearwater, Florida
https://a.co/d/03Mx6UyT
The sensor was AC Delco from Amazon, but I'm starting to think there is a chance it might be not be an authentic AC Delco part from some of the reviews:
https://a.co/d/0cpPaUqz
Last edited by Frankie15; Today at 07:03 PM.
Thread Starter
Melting Slicks
Joined: Jul 2016
Posts: 2,456
Likes: 495
From: Clearwater, Florida
Last edited by Frankie15; Today at 07:58 PM.
