Hey everyone. I have an 01 extreme which is overheating. I had a leak in the radiator two months ago. I replaced the radiator and driven 2,000 perfect miles since. When I got home last night I noticed the temp high. This morning it looked like I had a leaky cap since all the fluid was gone. I replaced that and drove for an hour or so throughout the day. Now my temp is hot again. Any advice is appreciated, thank you.

 

No, it would not. You have either burped air out of the system that got trapped during the radiator swap or you have a leak someplace. Since you replaced the cap and it is still getting low on coolant you need to look around really well to find the leak or have the system pressure tested to find it.
BTW, please use the 'edit' button to add or change a post if nobody has responded.

 

I filled it back up and ran it. It is leaking badly under the truck itself behind the oil pan. My research online tells me maybe the freeze plugs? If it is the freeze plugs, does that mean something else probably caused it? I have suspected my heater core to be bad since I have no heat. Can anyone offer advice. Thank you.

 

Could be leaking from where the heater hoses enter and exit the firewall for the heater core, could be the intake gasket leaking at the rear, etc. Somebody will have to physically look to find the source.

 

I will be calling someone tomorrow. Thanks again.