95seman

I just bought this car like 3 months ago and all I have had is problems. It started with radiator hoses to water pump to thermostat. To get the problem. I replaced the thermostat and seal. I have tried purging the system but it doesnt seem to be working. My car will stay at a good temp for maybe 5 mins and then overheat and I dont have heat anymore. My oil, plugs, and exhaust show no signs of a cracked head or blown head gasket and I am at a complete loss. I cant drive it so help me PLEASE. Thanx -Tanner