we just bought a 1992 Accord and my BF thinks that the cooling system is not getting as pressurized as it should. He took off the radiator thinking it might be clogged and it seems to drain fine. Further inspection, he noticed the water port on the head was black inside unlike another accord head we are rebuilding which is clean looking. what is the black stuff inside? pictures posted of both heads.

 

It could be some form of cooling system sealer goop. Have you done a compression test or was the cooling system loosing fluid?

 

So aside from not enough pressure, are you having a cooling issue?

Loss of coolant/low coolant level?

Overheating engine?

If it is just a lack of pressure building up you could do a pressure test on the cooling system or replace the rad cap.



I agree that the black/metallic coating could be some sort of quick fix sealer that had been used. Or some sort of snake oil extra cooling additive.

 

No, there were really no other issues known as we had just gotten the car. Just worried about the lack of pressure. We replaced radiator and it seems to be good now.