Jump to content
  • Sign up for FREE! Become a GM-Trucks.com Member Today!

    In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience. 

Coolant changed, and then...

Recommended Posts

2001 2500HD 6.0


Took my truck to a national chain that I've used before and Trust. Never mind which one. Had the coolant changed and some other front end issues worked on this past Saturday.


When I left it was a little warm so I was running my air conditioner. Then yesterday it cooled off quite a bit so I turned on the heater and a few minutes later the low coolant light came on. I started to drive home anyway thinking it was maybe just a little bit low. But I hooked up Torque application using my OBD2 diagnostic in the coolant temperature was steadily Rising. I decided to take my truck back to work and drive a work truck home.


Here is where I admit some ignorance about the procedure and I wonder what might have happened.


When the coolant is flushed, aren't they supposed to run it through the heater core somehow? Or maybe they did and then it had an air bubble in it and so it didn't fill the heater core?


Or maybe there was a very large air bubble somewhere else in the system?


I did check the Overflow container and it looked empty but it was dark. The engine was fully warmed up.


So what could have possibly happened or what did they forget to do? Or maybe it just needs a little more coolant?



Edited by brainpause
Link to comment
Share on other sites

Yeah, it just sounds like they didn't run it after the changeout to get all the air pockets out.  After you ran it, the air came out and the coolant in the reservoir flowed back in to take up the air space.  Just top off your reservoir or take it back to them to do it.



Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.