I have a 04 Grand Marquis with 75000 miles I also
a rattling noise in my engine when I turn on the
A.C. and drive what could it be
The AC clutch is most likely the problem rattling, replacement time.
Check as stated above the A/C clutch followed by the serpentine belt tensioner and idlers.
Okay I know what the serpentine belt are but what are tensioner and idlers
Tensioner is a spring loaded belt pulley that keeps tension on the belt. Idler is a belt pulley that the belt runs on. You should have someone look at it for you.
Looking for a Used Grand Marquis in your area?
CarGurus has 1,597 nationwide Grand Marquis listings starting at $1,000.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts