Originally posted by VTEC
$70 and a cooling system diagnostic later, I was told that exhaust gas is in the coolant.
For $70, they should tell you what was causing it. Any idiot (no insult intended) can tell if combustion chamber gasses are leaking into the cooling system.
My guess would be the head gasket. Remove head, replace gasket, reinstall head. Easier said then done, but it is by no means hard.