1998 Mercury Grand Marquis Problems

What owners report

Owners of this model year most often describe a cracked plastic intake manifold that leaks coolant, along with worn front-end steering and suspension parts and intermittent exterior lighting failures. Complaints cluster at higher mileages, roughly 60,000 to 130,000, though some front-end and trim reports come in at very low miles.

1. 1
   Engine cooling

   Cracked plastic intake manifold leaking coolant

   • 11 complaints (8%)
   • median 102,281 mi at 12.4 yrs old (9 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 2004–2018

   Complaints describe coolant pooling on top of the engine, often near the thermostat housing, and a check engine light that comes on and stays on. Some owners report overheating, misfires and rough running after coolant reaches the ignition coils, and a few describe the engine stalling. Owners who raised the part with dealers say they were told a coverage program on the manifold had expired or did not apply to their vehicle, and several paid for the repair themselves. Mostly reported between roughly 64,000 and 136,000 miles, often during normal driving rather than in any particular climate.

   1 related service bulletin

   What to check: Look for coolant residue or staining around the thermostat housing and the front of the intake, and ask whether the manifold has ever been replaced. A service bulletin in the input describes an extended coverage program for the composite intake manifold, so ask whether that program was ever applied to the vehicle.

   2 excerpts from owner complaints in NHTSA records

   “The plastic intake manifold in my 1998 Grand Marquis has cracked resulting in engine coolant fluid leak and engine failure. It is being repaired today. The car has approximately 87,000 miles. I understand that this occurs because of the material used for the intake manifold. The car is in otherwise very good condition.”

   NHTSA complaint #10307810, filed 2010-02, 88,000 miles

   “I observed a coolant leak around the thermostat. I found the plastic intake manifold to be cracked around the thermostat and leaking coolant. I made contact with Mercury and found that there had been a recall on the plastic intake manifold in which they would have replaced the part at no charge during the safety recall campaign. I was not made aware of the safety recall and have owned the vehicle since 04/17/02 when I purchased the vehicle used from a Mercury dealership. …”

   NHTSA complaint #10574132, filed 2014-03, 102,281 miles
2. 2
   Steering

   Front-end steering and suspension wear

   • 16 complaints (11%)
   • median 83,400 mi at 10.9 yrs old (9 state mileage, few)
   • 3 mention a crash, fire or injury
   • filed 1998–2020

   Owners describe tie rod ends separating, ball joints and other front-end parts failing, and loose or sloppy steering. Many reports mention squeaking, creaking or banging from the front end that a mechanic attributed to sealed components that cannot be greased. Several owners say the front end was rebuilt with greasable parts, and a few describe the steering wheel moving side to side on its own. Reported from about 50,000 miles upward, with several cases in the 80,000 to 121,000 range during normal driving at low and highway speeds.

   What to check: Have a mechanic inspect the tie rod ends, ball joints, idler arm and pitman arm before purchase, and listen for creaks or clunks over bumps on a test drive. Ask whether any front-end parts have been replaced and whether they are greasable.

   2 excerpts from owner complaints in NHTSA records

   “My 1998 Mercury Grand Marquis at slow speed had the passenger side tie rod end fail and fall off causing complete loss of steering. This happened at a slow speed luckily no accident. Car towed to ford dealer. Replaced all four tie rod ends. Cost $400.00. Car had 50,000 miles , this was a factory defect. This is a sealed unit requiring no grease or maintenance. I replaced with greased tie rodends.I believe this should be a recalled part.”

   NHTSA complaint #10200018, filed 2007-08, 50,000 miles

   “Autozone- valucraft brand- ball joints part number vfa2101 I recently had my ball joints replaced and I had a premature failure of the ball joint fastening hardware while driving down the city road in a straight line at 45 MPH. It caused thousands of dollars of damage and it also almost cause me great injury. I suspect autozone is using low grade nuts cause the nut that was on the ball joint sheared off causing me to bend a control arm, crack my frame, blow a tire, all while barely missing a telephone pole. …”

   NHTSA complaint #10861946, filed 2016-04, 213,760 miles
3. 3
   Exterior lighting

   Headlights and interior lights cutting out

   • 13 complaints (9%)
   • median 109,000 mi at 17.8 yrs old (7 state mileage, few)
   • filed 1999–2018

   Complaints describe headlights, tail lights and dashboard lighting flashing off and on or failing altogether while driving, sometimes at highway speed at night. Several owners say a dealer or mechanic identified the lighting control module as the cause, and a few mention the part being on back order. Some also report clouded or deteriorated headlight lenses that throw poor light. Spread widely, from a few thousand to about 165,000 miles, with many reports in the 86,000 to 136,000 range.

   What to check: Check that all exterior and dashboard lights come on steadily and operate the headlight switch through its positions, including high beam, while watching for flicker. Ask whether the lighting control module has been replaced.

   2 excerpts from owner complaints in NHTSA records

   “Light switch fails while lights are on high beam for one to two hours. Has happened four times while driving at 70 mpr on interstate 95.all interior and exterior lights blink off, then back on, then off several times before pulling to side of road... Has not happened while using low beams. Strikes fear in me and family each time it happens... I understand it common to my yr and make...what to do??”

   NHTSA complaint #10000643, filed 2002-12, 71,000 miles

   “My 1998 Mercury Grand Marquis headlights as well as tailights fail. During this all of a sudden while driving at night the headlights while driving will start flashing on and off, then just completely go off, as well as the lights on the doors and light around the dash controls such as (AC buttons an knobs) this happened rarely, but now it happened every single night. I googled this and many more are having the same problem, it seems as if its common in these vehicles. …”

   NHTSA complaint #10394258, filed 2011-04, 136,000 miles
4. 4
   Vehicle speed control

   Cruise control and throttle response problems

   • 6 complaints (4%)
   • median 56,500 mi at 10.9 yrs old (2 state mileage, few)
   • 3 mention a crash, fire or injury
   • filed 1999–2011

   Owners describe cruise control that will not engage, unusual fast idle after startup, and in some cases sudden or unintended acceleration or sluggish acceleration that requires pumping the pedal. Some complaints describe engine compartment or dashboard fires, and several owners say they were told their vehicle was not covered by a speed control recall. Mostly reported between about 50,000 and 63,000 miles, in some cases on vehicles that had been parked or driven at highway speed.

   Recall 07V336000Recall 08V051000

   What to check: Ask whether the speed control deactivation switch recall work has been completed for this vehicle, and test that cruise control engages and releases normally on a test drive. Note any strong idle flare after a cold start.

   2 excerpts from owner complaints in NHTSA records

   “Dt: the caller said her car burned up in 2000. Now she is finding out about the investigation into the cruise control fires. She believes that the car should be included. At the time she was told to call the insurance company, they said to call manufacturer, and she was getting the run around. She saw on cnn and the newspaper about the current problem they are having and wanted someone to help her. There is a fire report. The vehicle fire was contained to the engine compartment and dash area.”

   NHTSA complaint #10126197, filed 2005-07

   “Ltr fm louis hettinger(ky) owner of a 1998 Mercury Grand Marquis 4-door vehicle question if vehicle should be recalled because of fast idle. The iac valve was replaced on the vehicle but did not help the problem. The service dealer stated that there was nothing else they could do to resolve the issue. There were other consumers who experienced the same problem. (there was a fast idle upon start up and the vehicle would slow down at short notice. When the problem occurred, there was no way to control the vehicle)”

   NHTSA complaint #10046563, filed 2003-11
5. 5
   Electrical system

   Electrical faults and stalling

   • 6 complaints (4%)
   • median 66,000 mi at 7.1 yrs old (3 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 1999–2009

   Complaints describe the engine cutting out at speed with loss of power steering and power brakes, and in some cases a no-start condition that persists after replacing the battery, alternator, regulator and wiring. A few owners report smoke and a rapid clicking noise from the dashboard area, which a dealer traced to the radio and surrounding wiring. Some say no diagnostic trouble code was found when the fault was intermittent. Reported across a wide mileage range, from about 34,000 to 95,500 miles, often as an intermittent fault.

   2 related service bulletins

   What to check: Ask whether the car has ever stalled, and check service records for repeated battery, alternator or wiring repairs. Look for a battery warning light that stays on and note any burning smell or clicking from the dash.

   2 excerpts from owner complaints in NHTSA records

   “I have had all of my electrical components fixed, the alternator,the regulator,all the pig-tails,and a new battery. I am still having a problem with the battery light coming on. I have paid out alot of money to fix the problem. I am a tow truck driver and I tow alot of vehicles of this make and model for the same reason.”

   NHTSA complaint #10275820, filed 2009-07, 95,500 miles

   “Electrical short on 1998 Mercury Grand Marquis causes engine to stall at highway speeds. Power brakes and steering not operable when engine stalls. Cannot restart engine when condition occurs. Car towed all three times. Problem documented in ford service bullitin 12950. Problem occured 3 times: november 2003 october 2004 november 2004.”

   NHTSA complaint #10104447, filed 2004-12, 34,032 miles

Buying note. On this model year, focus the inspection on the plastic intake manifold for coolant leaks, the front-end steering and suspension parts, and the lighting and electrical systems, since those account for most of what owners describe. Completing any open speed control recall work and asking for repair records on those items is more useful than looking at mileage alone.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.