Header tank full of gunk
Hi all, iv recently just purchased a 2003 Mini Cooper s. 6 speed man. 90 k on clocks full service history, new engine and supercharger in 2010 invoice and receipt within service history. All the usual bits tht go wrong have bin done ie power steering etc.
any way I got it back, drove spot on, kept cool, below half way, didn't get hot, I checked the water resoviour and it was full of gunk, like old coolest, but the liquid under neith it was clean, I took it to my mates garage and we flushed the system and cleaned the header tank out, I ran it for 50 miles with water, distilled, we then re flushed the system and filled it with coolest, iv done about 150 miles with no rise I'm temp and iv gone today and re checked it and it's back to a horrible dark thick substance. I don't think the head gasket has gone it's not a milky colour, iv read they have a problem with the heat exchange where it cracks and the oil will mix with the water in there, can anyone shed some light please