I have almost the exact same problem. My coolant temperature gauge doesnt work, it points to the left. And just today i smelled coolant and i opened my hood and it was boiling/bubbling out of the overflow resovoir. I do not have a CEL tho.

Check this out, http://www.fastcougar.com/forums/messageview.cfm?catid=10&threadid=114933
The red is the sensor for the coolant temperature gauge, the green is the sensor the for computer. We have something messed up with the red sensor or the wiring for the red sensor. I really wish my temperature gauge was working so i know if im overheating or not. Where do you get the replacement water pump at with the metal impellar, ive searched but couldnt find anywhere? Please help me out desiato . I also have this post over on NECO stating my problems. http://www.fastcougar.com/forums/messageview.cfm?catid=10&threadid=124574

Mike