I just converted to an lt1 intake, and ran cooling lines from the heads to the heater core and back to the remote thermostat housing. Only one side goes through the heater core. The car continuously overheats, the temp gauge reads 240-250 before I kill the car. I know it's getting that hot because my secondary fan comes on. My primary fan, however, doesn't come on. It works, it'll come on when I jump terminals A and B to pull codes. Other than that it won't come on. Also, my radiator hose from the thermostat housing back to the radiator doesn't heat up. I have about 6 feet of cooling lines (3/4") from each head to the thermostat housing. Am I not getting any heat transfer through the cooling lines? Is that why my fan won't kick on? If that's the case, then my thermostat probably isn't opening either. How can I remedy this? I'm kind of on a budget, so I want to work with what I've got. Will drilling a few holes in the thermostat remedy my problem? Thank you for your help guys.

 

this might sound stupid....but you did refill with coolant again correct?

work the system free of airpockets? if it were me,id check those first off...and then replace thermostat.

before drilling holes...first check for proper tstat operation,boiling water on the stove is enough{if your that tight on funding}

 

Bottom line. The water pump must be able to circulate the coolant within the block. If all you have is a thermostat housing the coolant is not circulating throughout the block until the thermostat opens. You must route the coolant to the radiator two ways, the first is what you mentioned-through the thermostat. But there must be some coolant flow to the radiator at all times. On the 91 Z28 I have there was the standard TPI intake that had the thermostat and the large upper radiator hose. But there was also a routing of hoses that flowed coolant through the throttle body, to the heater core, around under the oil pan to the oil cooler then all the way back out to the passenger side of the radiator. This long routing of hoses and tubing was free flowing without any type of thermostat to restrict the flow of coolant.