overheating

[ezlie]

95 Roadmaster stationwagon overheated after small elbow joint hose failed. It was, along with one another hose, replaced. Drove away and overheated again. Replaced all hoses and overflow cap. As before, checked for air in line and pressure tested. Drove away and overheated. Despite not seeing any leaks, water pump and thermostat were replaced, coolant was tested for oil and oil was tested for coolant. Drained radiator to test flow in and out bottom as even flow (fine). After running engine, the radiator was laser tested for even heat (fine). Drove away and overheated again. The car performs excellently until it overheats. The fans are working. The radiator is about 14 months old (it was replaced when corrosion was found in radiator and causing overheating at that time). Despite no apparent performance problems, I am being told that the problem must be related to the intake manifold, the head gasket, and/or some other engine problem causing the overheating. I am looking for some magic bullet possibilities that won't involve messing with the engine.

 

[MrBuick (Magnum)]

One thing we can check off the list: the intake manifold gasket never comes into contact with the coolant. So that's not it. Blown head gaskets on these engines are fairly uncommon. If it passes a coolant pressure test I would not think head gasket. What is VERY common though, is to not bleed the cooling system properly on an LT1. The nose needs to be slightly higher than the ass. Start it up, and open the bleeder at the water pump. Do that until the air is all gone. Might need to be done a few times. Air pockets are a bitch on these cars.

 

[Buffman]

Can be done on a cold engine if you have the nose up, open the bleeder, open epansion tank cap, put rag over opening then using your air pushing power (your mouth) to pressure size the system. I made a cap to do it, and would push it at like 5 psi or something.

IS your heater core clogged? Do you have the correct LT1 thermostat?