So my zx2 is having some issues. It seems as though the cooling fan isn't coming on when it's supposed to. My car has a tendency to start boiling over after shut down. Boils over with the gage only halfway hot. I've flushed the system, it was pretty gunked up. It's only recently been getting gunked up as well. It was fairly clean when I swapped the water pump. Put fresh in and now gunk everywhere. Doesn't look like oil but could be gasket material?? Looks sludgy but feels gritty? Replaced the cap, thermostat, and the fan motor. The fan motor engages when tripped. Possibly that switch? I should also mention that it's been kinda doggy on take off. Replaced every vacuum hose I've seen. I'm preparing to yank the intake manifold to check/replace the gasket. It's a clean car, came with documented maintenance. I take good care of it and just wanna see it keep going. Anyone have any ideas? I would greatly appreciate any help.