why the heater wont get hot

Asked by Nov 12, 2013 at 10:26 PM about the 2004 Mercury Grand Marquis GS

Question type: Maintenance & Repair

heater want get hot

5 Answers

okay....the thermostat is stuck open...hopefully you've had a coolant flush as this will fail if the coolant is old and mucky~...so get new 50/50 mix and a new thermostat~https://www.google.com/#q=2004+Mercury+Grand+Marquis+ther mostat&tbm=shop&spd=3176755226586382219

3 of 3 people found this helpful.

Don't buy the 50/50 mix! A couple bucks more you can buy straight anti-freese and have 2 gallons of 50/50 mix. In stead of one gallon for a couple bucks more


50/50 mix is 50% anti freeze and 50% water why not buy straight anti freeze and mix it your self? You will twice the amount for your money

1 of 1 people found this helpful.

if both heater hoses are hot its inside the car diverter flap, if one is hot its the clogged core, if both mild its the stat

3 of 3 people found this helpful.

if the thermostat was stuck a code would be set and the check engine light would come on. most likely have a bad temp blend door actuator as stated by jimmy. very common on these and vary hard to get to. dash has to come out.

2 of 2 people found this helpful.

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