hey been a coulpe of weeks since i been on here, just a bit of a update, when i remove the heater pipes and flush the matrix put the pipes on they blow warm, but i noticed yesterday the pipe which comes off the cylinder head when squose togeher i can feel air rushing past, now i think the matrix is a place for the air to be caught, this is my theory on the heaters blowing cold,however when i flush the matrix and then take it the car on a good run the heaters blow warm for around 2 weeks, so kinda stuck! i would of thought if it was the head gasket i would be loosing water or burning oil or ove