I just purchased an 03 impala and i checked my radiator i have a build up of gunk in it i believe it is from using the wrong antifreeze but i am not sure anyway there also seems to be a leak from the head gasket on the forward head is there a default with that engine in these terms or should i just flush the radiatr and see what happens and can i change the transmission fluid myself or do i have to take it to a shop to change it?
Get this checked more closely it is more likely the intake gasket is leaking and the cooling system will need a thorough flush. The trans pan comes down, the fluid is drained, filter changed, about 7 qts of Dexron 111, messy job.
