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Mercury
Grand Marquis
30

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: 102,487 (23,000–170,000)
11 model years affected: 1994, 1995, 1996, 1998, more1999, 2004, 2005, 2007, 2008, 2009, 2010
30 people reported this problem
Comments
Viewing 1 - 13 of 13 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.
Sitting in my car with it idling and ac running on a cool morning after driving about one mile and I happened to notice the temp gauge had climed almost to the red in 20 minutes time. As I was driving home car cooled off but tried temp tried to inch back up if I stopped at a red light
While driving the car normally and no AC on, it won't overheat. When i turn the AC on the temperature starts to rise slowly. I haven't replaced anything on the car yet, but there are no leaks. I keep hearing thermostat or water pump or radiator or hoses. My question is, if it were to be one of those things wouldn't it overheat no matter if the AC was on or not?
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.
Blowing fuse with ac on. Only. No ac on cooling fan working great. New fan new relay evaperater coil is super hot in front of the radiator