1999 GMC ENVOY User Comment / Complaint

I have had to replace the heater core 5 times. the first time was 1 month after i purchased the jimmy used at reedmans auto world in pa. 2 months after that it was replaced again 6 months later and every winter since. i have heard there was a ionic problem with the jimmys that send and electrical current the motor, causing the heater cores to just eat away causing them to be replace. i have also had the upper and lower ball joints replace since i have had the jimmy( they were also replaced by the original owner. i have had to replace the engine mounts and my readitor since the motor mounts broke and sent the engine thru my radiator. all problems were fixed mostly at the dealer. however. the heater core has now blown again i have no heat or air. if i turn them one the coolant gushes out of the car. i no longer have a extra warranty(expired 8/06) and cannot get it fixed.. nothing seems to correct the heater core problem. 8ak