Originally Posted by Snyperx
Is the coolant draining really needed? I need to replace my gasket and really do not want to have to drain and fill the coolant as well.
The OP who wrote this DIY did not drain the coolant, so it is not necessary to drain the coolant. I did drain the coolant because I was concerned that when the oil filter housing was off the head, residual coolant could spill from the housing into one of the oil passages. It wouldn't be a lot and not a big deal, but why get the coolant mixed up with the oil when it can be easily prevented (kind of why you are replacing the gasket anyway). Secondly, if you leave to cooling hose connected to the oil filter housing, you now have stress to overcome from flexing the hose to move the oil filter housing out of the way, which IMO makes it harder to get a good shot at cleaning the housing and head gasket surfaces and could make it more difficult to properly seat the new gasket when reinstalling the oil filter housing.
Draining and refilling the coolant is so easy on this car it is almost ridiculous. And for the oil filter housing gasket procedure, you only need to drain less than half the coolant (about a gallon) to get the level below that of the head (so it doesn't spill out). Partially draining, refilling and bleeding the coolant adds maybe 30 to 40 extra minutes to the job. I made sure everything was clean and reused my coolant since it was only a few months old; I strained it into an old coolant bottle using a blue paper shop towel.
Just my $.02.