Hello, I am new to posting. I have an 86 GL EA82 with 190,000 that keeps overheating. I never let it go in the red, but it gets up there, then I turn the heater on and it goes down. In the winter, its cold here, no probelms, just the summer. Timing belts were replaced, flushed the radiator ( myself), everything else seems to be in good working order. He doesnt smoke or use oil. Does have a slight lifter tap but thats it. What else can it be? I was thinking of having a professional radiator flush or getting a new radiator but dont want to waste the money if it wont fix it. Could the head gasket be leaking without major symptoms? Is there something I am missing. Any help is appreciated, Thanks- Chris