your resovior might be blown, when i bought my car, for some reason my cooling fan was unlpugged and my car would overheat real fast...the temp would rise faster everytime i drove the car...until my resovoir blew up and i could barely make it to the dealership...does it overheat too?...but it is possible that your resovoir could be cracked...possibly a hose tho, that would be a cheaper fix if it is...