I have a 2006 magnum rt. I am trying to fill the cooling system. You are supposed to remove a plug on the thermostat housing and replace it with a bleed valve. That plug is all messed up and I can't get it out. Any suggestions? Is there another way to fill without changing the plug to a bleed valve?

 

Lots of thermal cycles (run to temp & cool down) combined with burping the system constantly (opening the cap on the surge tank to let the air escape). Just make sure the car has had a chance to cool down first before touching the cap. Top up as needed. Don't mix the different types of coolant or you're gonna have a very bad week.

 

I was able to use an angle drill, cut down drill bits and EZ out to get the plug out and replace with a bleed valve. What a job.