The composite (plastic) intake manifold may crack near the thermostat housing and cause a coolant leak. Ford released an updated manifold that was reinforced to prevent a recurrence. No recall was issued for this problem but Ford did extend the warranty to seven years on some models from the date of purchase.
Resources for the Repair and Maintenance of your 1999 Mercury Grand Marquis
1999 Mercury Grand Marquis
1999 Mercury Grand Marquis Problems
The throttle position sensor (TPS) may fail. Common symptoms of a defective TPS can be rough idle, hard starting, hesitation on acceleration, poor fuel economy, and stalling.
A spring in the seat belt buckle may wear or fail, causing the airbag light on the instrument panel to illuminate. Failed buckles will require replacement.
The heater hose outlet may leak coolant at the back of the intake manifold. Sometimes this is misdiagnosed as a leaking intake manifold gasket because it resembles a leaking manifold.
1999 Mercury Grand Marquis Recalls (Recent)
Summary: VEHICLE DESCRIPTION: PASSENGER VEHICLES. THESE VEHICLES HAVE JACKING INSTRUCTIONS WHICH, IF FOLLOWED, COULD CAUSE THE VEHICLE OPERATOR TO PLACE THE JACK ON A FRAME WELD WHEN ATTEMPTING TO RAISE A REAR WHEEL. IF THE VEHICLE IS JACKED UP WITH THE JACK PLACED ON THE FRAME WELD AND IF THE VEHICLE IS FREE TO ROLL (WHEELS NOT BLOCKED OR CHOCKED), THE JACK COULD YIELD AND THE VEHICLE MAY DROP SUDDENLY.Learn more »
Summary: VEHICLE DESCRIPTION: PASSENGER VEHICLES USING AFTERMARKET FRONT PASSENGER SIDE SEAT BELT ASSEMBLIES THAT WERE SOLD BY FORD PARTS DEPARTMENTS FROM JANUARY 1, THROUGH JUNE 13, 2000. THESE SEAT BELT ASSEMBLIES FAIL TO COMPLY WITH THE REQUIREMENTS OF FMVSS NO. 209, "SEAT BELT ASSEMBLIES." THE EQUIPMENT INVOLVED IS SERVICE STOCK SEAT BELT ASSEMBLIES, MODEL NOS. H 9977, H 9979, T 9063, AND T 9217, BUILT BY TRW VEHICLE SAFETY SYSTEMS, INC. (TRW) MANUFACTURED FROM JUNE 1, 1998 THROUGH MAY 21, 2000. SOME OF THESE SEAT BELT ASSEMBLIES MAY HAVE BEEN INSTALLED AS SERVICE REPLACEMENT EQUIPMENT ON THE VEHICLES INVOLVED IN THE RECALL.Learn more »
Summary: VEHICLE DESCRIPTION: PASSENGER VEHICLES USING AFTERMARKET DRIVER'S SEAT BELT ASSEMBLIES THAT WERE SOLD BY FORD PARTS DEPARTMENTS FROM JANUARY 1, THROUGH JUNE 13, 2000. THESE SEAT BELT ASSEMBLIES FAIL TO COMPLY WITH THE REQUIREMENTS OF FMVSS NO. 209, "SEAT BELT ASSEMBLIES." THE EQUIPMENT INVOLVED IS SERVICE STOCK SEAT BELT ASSEMBLIES, MODEL NOS. H 9977, H 9979, T 9063, AND T 9217, BUILT BY TRW VEHICLE SAFETY SYSTEMS, INC. (TRW) MANUFACTURED FROM JUNE 1, 1998 THROUGH MAY 21, 2000. SOME OF THESE SEAT BELT ASSEMBLIES MAY HAVE BEEN INSTALLED AS SERVICE REPLACEMENT EQUIPMENT ON THE VEHICLES INVOLVED IN THE RECALL.Learn more »
1999 Mercury Grand Marquis Questions and Answers
while car is in garage, lights will come on and off intermittently,I have turned the autolamp to OFF position, but problem still occurs. What can be done? Must stay on for long periods too as batte...
left turn steering occasionally is like manual steering with a knock.
While driving Last week my service engine light came on. I then noticed that the cooling fan would come on, even when starting the car or driving only a short distance. Are the 2 related ...
The check engine light comes on and the cooling fan runs even when car is cold - put an obd scanner on it and comes up with error code P0455 - Thanks for help
1999 Mercury Grand Marquis Reviews
I have had this car for only 6 months and already i've had to replace my alternator, my intake manifold, and my bearing. It only has 75k miles and mechanics keep telling me "it's in great condition" but considering I've dropped more money in 6 months on fixing it than I paid I would consider it to not be in great condition. Awful gas mileage, heat takes forever to start, etc. Would not recommend to a friend.
My 1999GM-LS runs well now 140,000 miles since new. Had AC control unit, fuel pump, Idle air control valve, rotors, cracked intake manifold replaced. Recently a slight vibration developed at idle when engine is hot. Most noticeable at steering wheel. Dealer can't find fault - deemed normal? Cracked intake manifold - is bound to happen when plastic bonded to aluminum. Grade school physics tells us that metal and plastic expands and contracts differently when temperature changes. can't believe any Ford engineer could overlook this?? when the GM was designed. Perhaps the plastic manifold are designed to fail!
1999 GRMARQUI Have TEPID HEAT.. Have changed thermastat flushed out heater core Still very LOW heat
Best car I ever had (and I had over 30 so far). Bought it used with 163,000 miles, and it drives way better than anything else I know.
Got my car 2nd hand at 120,000 miles. Just got 270,000 miles on it last week, avg 550 miles a week to work and back home. THe problems i have had are cracked intake manfold (plastic), air compressor, ac/hvac control mod ($500 new, $50 savage), and need to replace rotors (still first set). One coil pack to the spark plugs went bad, still drove on 7 cylinders (till i mad to to the shop). Still avg 23 mpg. The cat is starting to go that will be expensive. I love this car wish i could get another to replace this one when it finally dies.