Subeedoo

Not sure if you found your issue but I had a 2000 legacy with spuratic overheating. The headgaskets were good. Pulled the motor took the heads off and the block and heads, mostly on the 2 and 4 side appear to have a concrete type substance. The shop and I determined that it was most likely an overdose of stop leak. Since it wasn't me it must have been the previous owner.