That, or the gauge is going. Or a loose wiring connection. I'd bet on the last.
the tire pressure for most Grand Marquis models is 31 psi front, 35 psi rear.
In the trunk.
On the fuel rail.
34 lbs.is good all around
32 or 34 lbs. Your choice.
location of oil sencor
Have the high pressure valve checked.
Where is it located on the engine
do not put any pressure on shift lever until brake is pushed. also lift shift lever directly up when placing into reverse.
On a 1997 Mercury Grand Marquis : The thread on cap on the engine coolant reservoir is the 16 PSI pressure cap / radiator cap
On a 1997 Mercury Grand Marquis : The thread on cap on the engine coolant reservoir is your 16 PSI pressure cap / radiator cap
Listed in your owner's manual and on the driver's door post.