2006 Mercury Grand Marquis, 94K,
The last month the car has been making a knocking sound, it still runs great and the noise is most apparent when I stop at a red light or any sort of idle. As the car gets more warm, its less loud. Then, tonight I discovered that when I turn the AC off, that noise disappears altogether I think. Once I turned it back on, it was back. Just as I got home, I turned the AC on again and it was there. When I turn the car off, that noise is still going for 1-3 seconds. Like its a fan that's slowing down. Not a car guy, have no idea of anything but I know the sounds of this car because I have been driving a MGM for 35 years straight. Anyone have a clue?
Question: is this cooling fan the same as a fan that cools the radiator? location being right in front of a radiator?
At least one would be.
If so, why the noise only when the AC is turned on and then why doesn't the car overheat if this fan is now always off in the winter?
Many cars have a 2nd fan that turns on with the AC.
Why not just test the fan or fans and find out if that's what the noise is?
Check your cooling fan(s).
@chucktobias Question: is this cooling fan the same as a fan that cools the radiator? location being right in front of a radiator?
If so, why the noise only when the AC is turned on and then why doesn't the car overheat if this fan is now always off in the winter?
thanks, forgive me if the ?? are dopey because I know nothing about cars.