ye, drained it when i bought it. put a 75-25 mix in because winter was on its way. noticed there was no heat on the drive to mot (11 miles) and no heat on way back. checked the coolant level. still full but murky. rusty coloured. done the mot failures. thought the sound was manifold gasket or injector related (past experience) but done everything but checked the water pump. but dont want to waste more time or money on fixing what isnt broke!