Cyl Head Removal Observations

[canada karl]

Pulling the haed for blown head gasket.There seems to be a black tar like substance in the intake runners. Is this normal for an engine over 100km? There was motor oil in the intake plenum by the #6 runner?Is this normal? On the bottom of the intake plenum where the two hoses attach there's quite a bit of white powdery corrosion. What's the function of this component and should I take it apart and clean it? Is there any preventative maintenance I should be doing while I'm this area? Probably hoses for sure.