Grand Marquis

Engine May Overheat at Idle With AC On on Mercury Grand Marquis

Problem Description and Possible Solution

The engine may overheat at idle when the AC is on. A new, upgraded fan motor and resistor may be required to correct this concern.

Problem Data
RepairPal Verified
Average mileage: 92,434 (23,000–160,000)
9 model years affected: 1994, 1996, 1998, 1999, more2004, 2007, 2008, 2009, 2010
22 people reported this problem
Viewing 1 - 10 of 10 comments
The engine may overheat at idle when the AC is on. A new, upgraded fan motor and resistor assembly should be put in.
fan runs intermittently. obvious when a/c is on because if you are in stopped traffic/idling, it overheats. sometimes whacking cooling fan module or moving wires works, sometimes not. Fan was replaced 2 yrs ago. Trying to find module for easier repair.
Blowing hot air when idling or car was stationary. Drove it 15-20 miles....turned car off...started it up right away and the car made a strange sound and dumped contents of radiator....overheated. Dealership replaced fan and module $1000.
The a/c began blowing hot air with the a/c on while at idle waiting for a stoplight. Revved it up a bit to get cool air. This worked for the first couple of stoplights and then I suddenly noticed some steam coming from under the hood. I looked down at the temp gauge and saw it was almost into the red zone. The check engine light then came on , the car began missing badly and clouds of steam began coming from under the hood. I veered off into a nearby parking lot and stopped the car. The radiator continued to boil over and dumped about 2 gallons of coolant on the ground. I ran across the street bought a gallon of distilled water and a gallon of coolant. Carefully removed the radiator cap after it cooled down a bit and refilled the radiator with coolant mix, then went on my way after turning the a/c off and the heat on as a precaution of course. A little hot in the car on a 95 degree day. Haven't had trouble since but it's been in the 60s and 70s since. Same thing happend last year just before the a/c went totally out. I won't be happy if that happens again. Cost for this incident this year: $17.00 in water and coolant and about an hour and a half of my day.
MY 2004 Mercury Grand Marque over heated in June while I was waiting on a red light to change, dumping all fluid and stranding me.
I waited 2-weeks for my son to check out the car and he changed the thermostat and I drove it to the doctor next day and it over heated again. We added more antifreeze and I have not had that problem since, just a new host of problems. The A/C will only flow hot air, the passenger window if, I put it down it can only be put back up by force, the door can not be locked with the remote, I purchased a inside window washer and the long handle makes it easy to lock the door. My headlights went out and I also received the recall letter in April about that problem, the headlight problem did not occur till early on a very dark November morning when I was on my way to take my sister, for surgery, to the hospital.
My car is now at the dealership for all electrical problems to be fixed and I understand the headlight part my not be available for months. Happy days are ahead.