Ok i have a 1995 toyota corolla "japanese version" recently i had my engine head repaired I got a New head gasket , New Radiator , new water pump , new thermostat, new radiator cap , i even replace all of my hoses. when the car was completed it was running excellent but after driving it for a while, it will start making this rattling sound like its running hot ,but when i stop and i check the car everything seems to be fine the radiator has coolant , the hoses are not leaking coolant I mean the car isnt leaking coolant at all even My fan was working fine, so what i did i take out my thermostat and i didnt put a one in after i did that i didnt hear the noise no more but two days later while i was driving the noise came back again and it will only make the rattling noise after i drive the car for an hour? i juz dont understand? Could my engine head be causing all this trouble?