MileageCurve What breaks, and at what mileage

Pontiac Grand Am 1992–1998

4th generation · GM N-body · 3,204 complaints, 393 with mileage

Owners filed 3,204 complaints with NHTSA about the 1992–1998 Pontiac Grand Am, and 393 of them record the mileage at which the failure happened. That is enough to show not just what fails, but when.

49% of failures occur beyond 100,000 miles — a wear pattern. The car generally reaches substantial mileage before trouble starts.

The most-reported areas are the electrical system (19.7% of complaints, typically around 104,000 miles), the engine and its cooling system (14.9% of complaints, typically around 95,500 miles), the hydraulic brake circuit (14.1% of complaints, typically around 80,103 miles).

When failures happen

0–5k: 20 complaints (5.1%)0–5k5–10k: 2 complaints (0.5%)10–20k: 15 complaints (3.8%)10–20k20–30k: 9 complaints (2.3%)30–40k: 16 complaints (4.1%)30–40k40–50k: 19 complaints (4.8%)50–60k: 6 complaints (1.5%)50–60k60–70k: 22 complaints (5.6%)70–80k: 23 complaints (5.9%)70–80k80–90k: 30 complaints (7.6%)90–100k: 37 complaints (9.4%)90–100k100–120k: 57 complaints (14.5%)120–140k: 49 complaints (12.5%)120–140k140–160k: 31 complaints (7.9%)160–200k: 48 complaints (12.2%)160–200k200k+: 9 complaints (2.3%)570

10% of failures occur by 20,478 miles · a quarter by 63,095 · median 99,000 · three quarters by 135,000 · 90% by 172,000. Based on 393 complaints that record mileage.

What fails, and when

SystemComplaintsShareTypical mileageMiddle half
Electrical System63019.7%104,00074,000–143,723
Engine And Engine Cooling47714.9%95,50069,000–113,264
Service Brakes, Hydraulic45114.1%80,10345,000–133,000
Air Bags2517.8%125,14995,500–150,000
Visibility1765.5%74,62930,000–95,000
Power Train1715.3%95,55045,000–124,000
Steering1554.8%106,50082,000–158,824
Suspension1163.6%89,54850,000–142,572
Exterior Lighting1073.3%90,55122,000–128,728
Structure1013.2%99,00056,000–120,000

By model year

YearComplaintsWith mileage
19923047
199329015
199451537
199558749
1996672104
1997600124
199823657

Which systems, and when

Complaints about this generation are not spread evenly across the vehicle, and the systems that generate the most of them do not all fail at the same point in a car's life. The median failure across all systems here is 99,000 miles; the figures below show which parts of the car run ahead of that and which run behind.

The electrical system accounts for 19.7% of complaints (630 reports, 73 of them with a mileage figure), with a median of 104,000 miles, close to the vehicle's overall pattern. The middle half of these reports falls between 74,000 and 143,723 miles.

The engine and its cooling system accounts for 14.9% of complaints (477 reports, 70 of them with a mileage figure), with a median of 95,500 miles, close to the vehicle's overall pattern. The middle half of these reports falls between 69,000 and 113,264 miles.

The hydraulic brake circuit accounts for 14.1% of complaints (451 reports, 19 of them with a mileage figure), with a median of 80,103 miles, close to the vehicle's overall pattern. The middle half of these reports falls between 45,000 and 133,000 miles.

The airbag system accounts for 7.8% of complaints (251 reports, 70 of them with a mileage figure), with a median of 125,149 miles, close to the vehicle's overall pattern. The middle half of these reports falls between 95,500 and 150,000 miles.

Visibility equipment accounts for 5.5% of complaints (176 reports, 26 of them with a mileage figure), with a median of 74,629 miles, close to the vehicle's overall pattern. The middle half of these reports falls between 30,000 and 95,000 miles.

The transmission and driveline accounts for 5.3% of complaints (171 reports, 19 of them with a mileage figure), with a median of 95,550 miles, close to the vehicle's overall pattern. The middle half of these reports falls between 45,000 and 124,000 miles.

Differences between model years

Within this generation, complaint volume is not constant across model years. The 1996 model year drew the most — 672 complaints — while 1998 drew the fewest at 236. The median year sits at 515.

Recalls and what they cover

No recall campaigns covering this generation appear in NHTSA's post-2010 recall file. That is not the same as an absence of problems — recalls address safety defects specifically, and many of the complaints above concern faults that are expensive or annoying without meeting that threshold.

Reported severity

Of the 3,204 complaints filed against this generation, 279 reported a crash; 138 reported a fire; 323 reported an injury; 27 reported a fatality. Crash-involved reports represent 8.7% of the total.

These are owner-reported outcomes, not verified investigations, and they are not adjusted for how many of these vehicles are on the road. They are included because the distinction between a fault that strands a car and a fault that causes a collision is the one that matters most, and it is not visible in a complaint count alone.

What this means if you are buying one

For a buyer, a late-failure pattern shifts the question from whether to when. 49% of reported failures occur beyond 100,000 miles, so an example approaching that figure is approaching the range where other owners started reporting problems. The middle half of all failures falls between 63,095 and 135,000 miles.

On inspection, the electrical system and the engine and its cooling system are where this generation's reports concentrate, so those are the areas worth a specific look. The engine and its cooling system in particular shows a median failure mileage of 95,500, which gives a concrete number to compare against the odometer of any car you are considering.

None of this is a substitute for a pre-purchase inspection on the individual car. Aggregate patterns describe a population; the example in front of you has its own history.

Documented problems

Engine - intake manifold 1996-1998 (3.1L V6)

3.1L V6 lower intake manifold gasket degradation, allowing coolant into the crankcase and/or external coolant seepage; associated with Dex-Cool long-life coolant and the nylon-carrier/silicone gasket design used across GM 3.1L/3.4L 60-degree V6s. Subject of the GM Dex-Cool class action covering roughly 1995-2003 3.1L/3.4L vehicles.

Engine - cylinder head 1996-1998 (2.4L)

2.4L LD9 Twin Cam head gasket failure, often secondary to cooling-system neglect or overheating; also timing chain tensioner wear producing cold-start rattle.

Electrical - anti-theft 1996-1998

Passlock/VATS theft-deterrent system faults cause intermittent crank-no-start with the security lamp lit; the fix is typically the ignition lock cylinder housing sensor rather than the engine.

Body - windows 1996-1998

Power window regulator cable/pulley failure, most often the front doors.

What owners reported

1992 · 79,000 miles · Engine And Engine Cooling
I HAVE A LETTER FROM PONTIAC DATE NOV, 1995. WHICH STATES THAT 2.3L QUAD OHC ENGINE HAVE A DEFECT OF CRACKING CYLINDER THAT ALLOWS COOLANT TO LEAK FROM THE CYLINDER HEADS. THE LETTER ALSO STATES.. DO NOT BRING YOUR VEHICLE TO THE DEALER UNLESS THIS OCCURS. THE STATED IF THIS CONDITION OCCURS WITHIN SEVEN YEARS OR 100,000 MILES THEY WILL REPLACE THE CYLINDER HEAD FREE OF CHARGE.. MY CAR IS 8 YEAR…
1992 · 86,000 miles · Engine And Engine Cooling
COOLANT LEAKED FROM UNDERNEATH THE VEHICLE WHILE DRIVING ABOUT 50 MPH WHICH CAUSED THE VEHICLE TO OVERHEAT. *AK THE VEHICLE WAS TAKEN TO THE DEALER WHERE THEY DETERMINED THAT THE RADIATOR HOSE HAD A SPLIT IN IT. THE SAME WEEK THE VEHICLE WAS PURCHASED THE BRAKE LINE BROKE. ABOUT 2 MONTHS LATER THE BRAKE PEDAL WENT TO THE FLOOR WHILE BRAKING. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC W…
1992 · 86,000 miles · Service Brakes, Hydraulic
COOLANT LEAKED FROM UNDERNEATH THE VEHICLE WHILE DRIVING ABOUT 50 MPH WHICH CAUSED THE VEHICLE TO OVERHEAT. *AK THE VEHICLE WAS TAKEN TO THE DEALER WHERE THEY DETERMINED THAT THE RADIATOR HOSE HAD A SPLIT IN IT. THE SAME WEEK THE VEHICLE WAS PURCHASED THE BRAKE LINE BROKE. ABOUT 2 MONTHS LATER THE BRAKE PEDAL WENT TO THE FLOOR WHILE BRAKING. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC W…
1993 · 108,119 miles · Electrical System
VEHICLE WAS PARKED AND BEGAN SMOKING UNDER THE HOOD. AN INDEPENDENT SHOP STATED THAT SWITCH LAMP BURNED OUT CAUSING SMOKE IN THE STEERING WHEEL COLUMN. THE DEALER WAS NOTIFIED. *AK THE VEHICLE DIDN'T START. THE VEHICLE RECEIVED A JUMP, THEN THE VEHICLE STARTED. THE HEADLIGHTS WERE ON EVEN THOUGH THE SWITCH WAS OFF. THE SWITCH WAS UNABLE TO BE MOVED. THE BATTERY HAD TO BE DISCONNECTED BE…

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