Montana randomly overheats

[Joshschneids]

Just recently go a 2000 pontiac montana, fixed the head gasket leak, 3/4 of the time my heat works but the odd time ill drive from my house to my grandparents which is about 1 and a half km and the van will pin the needle in the red and my hot coolant level light will come on. If I pop the hood and look at my coolant reservoir it is almost full. Then if I keep driving the temp will go down sometimes. I I come out and start it 10 minutes later it will be fine coolant is regular level and it blows hot heat. What is causing this problem? Have thought of an air lock because if air expanding and pushing the coolant into the resivour. Sorry for the long explanation but I have troubleshooted this long enough an have become frustrated! Any help would be appreciated! Thanks, josh

 

[Steelcity]

sounds like air trapped in the system. try bleeding the system ,I think there is a bleeder somewhere near the thermostat . I have heard other members parking the van on a steep hill with the front end pointing up hill and running the engine running with the heat on and the rear heat on with the rad cap off and squeezing the rad hoses , kind of like burping the system. Good luck. keep us posted.

 

[Joshschneids]

Thank you steelcity I believe that's what it is I just got to get some time to do it , I have bled the system brier and air comes out I got to do that and add some coolant because I don't have any dex cool kickin around that will be my little weekend project