Temperature gauge doesn't move from cold
As you also have a check engine light, you may have a stuck open thermostat, first thing to check is the codes for the check engine light, if it says engine temp too low to reach closed loop then a thermostat is the most likely cause, but you could also have wiring or sensor/ sender problems, it is a 12 year old vehicle so things are going to start showing up.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts
Related Models For Sale