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1998 Buick Century

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1998 Century.

Body PASSENGER CARTransmission Automatic 4-spd

The 1998 Buick Century is a conventional passenger car motivated by a 4-speed automatic transmission and an engine requiring 4.5 quarts of 5W-30 API oil, returning an EPA fuel economy of 17 city and 27 highway mpg. Beyond its unremarkable commuter specifications, this model year carries a heavier burden of reliability concerns, logging 251 total owner complaints and four recalls largely centered around hydraulic service brakes. Sitting just one complaint below the 1999 peak within the 1990-2005 model history—a range that bottoms out at just 19 complaints in 2005—the 1998 Century represents one of the least dependable iterations of the nameplate for researchers to evaluate.

Model year2005 2004 2003 2002 2001 2000 1999 1998 1997

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4.5 qtOEM · verified

Engine oil type5W-30 APIOEM · verified

Lug nut torque100 ft-lbsOEM · verified

EPA fuel economy17/27/21 mpgEPA · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 78 · 600 CCA battery, OE oil filter 12731175. Note the factory fuel filter is now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 78 · 600 CCAOEM · verified

Tire sizeP205-70R15OEM · verified

Wheel / rim6-J inOEM · verified

OE service part numbers OEM · verified

Engine oil filter	12731175
Engine air filter	19166106
Fuel filter	25121293 discontinued
Spark plug	19301813
Front wiper blades	19120758
Serpentine belt	19244954
Thermostat	24507563 alt 10226107
Cabin air filter	84557894

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

Transmission

Automatic 4-spd

Dimensions & weight NHTSA vPIC

Overall length	194.5 in
Overall width	72.8 in
Overall height	56.7 in
Wheelbase	109.1 in
Curb weight	3362 lb
Track (front / rear)	62.2 / 61 in
Weight distribution (front / rear)	64/36

Ratings & economy EPA / vPIC

EPA city / highway / combined	17 / 27 / 21 mpg
Drivetrain	Front-Wheel Drive
Passenger volume	102 cu ft
Cargo volume	17 cu ft
Recommended fuel	Regular Gasoline

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4.5 qt of 5W-30 API engine oil. Torque lug nuts to 100 ft-lbs. The firing order is 1-2-3-4-5-6.

Lubricants & capacities

Engine Oil	5W-30 · API
Engine Oil Capacity	4.5 qt

Engine torques

Crankshaft Position (CKP) Sensor Bolt(s)	24X Sensor: 8 ft-lbs, 7X Sensor: 6 ft-lbs
Camshaft Position (CMP) Sensor Bolt(s)	8 ft-lbs
Camshaft Sprocket and/or Gear Bolt(s)	81 ft-lbs
Crankshaft Pulley and/or Damper Bolts	76 ft-lbs
Engine Coolant Temperature (ECT) Sensor Bolt(s)	17 ft-lbs
Oxygen (O2S) Sensor Bolt(s)	30 ft-lbs
Knock Sense (KS) Bolt(s)	14 ft-lbs
Exhaust Manifold to Cylinder Head Bolts	12 ft-lbs

Chassis torques

Lug Nuts	100 ft-lbs
Rear Wheel Hub	44 ft-lbs
Front Wheel Hub	159 ft-lbs

Ignition

Cylinder Firing Order	1-2-3-4-5-6
Ignition Coil Secondary Resistance	5,000-7,000 ohms
Spark Plug Manufacturer	AC Delco
Spark Plug Gap	0.060 in
Spark Plug Torque	15.0 ft-lbs

Battery & A/C

Refrigerant	R134a
Refrigerant Capacity	1.88 lbs
Oil Group	PAG
Oil Type	46
Oil Capacity	9.00 oz
Standard BCI Group Number	78
Standard BCI Cranking Performance	600 cca

Service checks

Pressure Test	16; Pressure should not exceed 20 psi.
Radiator Cap Pressure Relief	16 psi
Thermostat Opening Temperature	188-206 °F
Fuel Pump Pressure Minimum	47.0 psi
Key ON Engine OFF (KOEO)	40.5-47
RPM	30.5-44 @ Idle rpm
Injector Primary Resistance	11.8-12.6 na ohms
Engine Compression	100

Brakes

Brake Application	WITH REAR DISC
Torque Caliper to Bracket	32 ft-lbs / 137 ft-lbs
Torque to Knuckle	92 ft-lbs / 100 ft-lbs
Minimum Pad Thickness	Front: 0.030; Rear: 0.030 specification
Brake Application	WITH REAR DISC
Rotor Max Parallel Variation	0.0005 in
Rotor Runout Limit	0.003 in
Rotor Nominal Thickness From	0.43 in / 1.27 in

Multi-step torque procedures OEM · verified

Cylinder Head — tightening sequence 2 stages

1	44 ft. lbs.	44 ft. lbs
2	turn 95

Engine Valve Cover Bolts — tightening sequence 1 stages

7.4

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 7,500 mi; spark plugs every 100,000 mi; coolant at 150,000 mi. The big-interval services (at 150,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

Every 7,500 mi	Brake System (inspect) · Door Hinge (lubricate) · Engine Oil (drain & refill) · Engine Oil Filter (replace) · Hood Hinge (lubricate) · Hood Latch (lubricate)
Every 15,000 mi	Cabin Air Filter (replace)
Every 30,000 mi	Engine Air Filter Element (replace) · Fuel Line (inspect) · Fuel Tank (inspect) · Fuel Tank Filler Cap (inspect)
Every 60,000 mi	Accessory Drive Belt (inspect)
Every 100,000 mi	Spark Plug Wires (inspect) · Spark Plugs (replace)
At 150,000 mi	Engine Coolant System (drain, flush & refill)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

The 1998 Buick Century sits at the apex of the generation’s complaint curve, with 251 complaints more than doubling the 120 filed in 1997 and far exceeding the 99 recorded for 1996. This year initiates the model’s highest-complaint period, nearly matching 1999’s 252 reports, while investigations reached a series high of four and recalls held at four on the way to a seven-recall peak in 2000. Compared with the early 1990s, when annual complaints ranged from 46 to 52, and the downward trajectory that emerged after 2000, 1998 represents a clear inflection point of intensified owner reports. Federal records show the most frequently cited issues involved Service Brakes, Hydraulic; Power Train; Visibility; and Exterior Lighting, though the data does not specify underlying root causes. The model year generated nine crash-related complaints and zero fire-related complaints. Because 1998 stands at the peak of the generation’s complaint and investigation activity, it is not a favorable year to buy relative to lower-complaint alternatives such as 1996 or the 2004–2005 model years.

Open recalls

NHTSA campaigns

Service bulletins

Manufacturer communications

ODI investigations

Office of Defects Investigation

251

Owner complaints

9 involved a crash · 0 a fire

Owner complaints by model year NHTSA · this generation & adjacent

’90 ’91 ’92 ’94 ’95 ’96 ’97’98’99 ’00 ’01 ’02 ’03 ’04 ’05

Owner complaints filed with NHTSA, by component

All 251 complaints on record, top 8 components.

Service Brakes, Hydraulic26

Power Train24

Visibility23

Exterior Lighting20

Electrical System19

Steering18

Engine & Engine Cooling18

Unknown Or Other12

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 4 campaigns on record for this vehicle.

09E005000SteeringReported 17/02/2009

DORMAN IS RECALLING 979 STEERING KNUCKLES, DORMAN P/NOS. 697-902 AND 697-903, SOLD UNDER DORMAN'S "OE SOLUTIONS<SUP>TM</SUP>" BRAND NAME, AND NAPA P/NOS. 7-8502 AND 7-8503 WHICH WERE SOLD FOR REPLACEMENT USE ON THE… Remedy: DORMAN WILL NOTIFY OWNERS AND REPLACE THE DEFECTIVE STEERING KNUCKLES FREE OF CHARGE AND REIMBURSE THE REPAIR FACILITY OR OWNER FOR LABOR. THE RECALL BEGAN ON FEBRUARY 23, 2009…

99V356000Exterior Lighting:HeadlightsReported 17/12/1999

VEHICLE DESCRIPTION: PASSENGER VEHICLES. THESE VEHICLES DO NOT CONFORM TO THE REQUIREMENTS OF FMVSS NO. 108, "LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT." THE VERTICAL HEAD LAMP ADJUSTING DEVICE MAY NOT BE… Remedy: OWNERS WILL BE PROVIDED WITH AN OWNER'S MANUAL INSERT CONTAINING INSTRUCTIONS FOR OPTICALLY AIMING THE HEADLAMPS.

Technical service bulletins NHTSA · verified

Showing 5 of 95 bulletins on record with NHTSA.

Bulletin	Date	Component	Summary
PIP4723F	2022-01-14	Service Brakes, Hydraulic	This Preliminary Information communicates to the dealer the process for downloading or…
PIP4723D	2020-01-31	Electrical System	This Preliminary Information communicates to the dealer the process for downloading or…
PIC4696E	2019-11-22	Equipment	This Preliminary Information communication provides information to the technician on how…
PIC4696D	2019-09-05	Equipment	This Preliminary Information communication provides information to the technician on how…
PIC4696C	2018-05-31	Equipment	This Preliminary Information communication provides information to the technician on how…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420

Catalyst system efficiency below threshold — Bank 1

P0300

Random / multiple cylinder misfire detected

P0171

System too lean — Bank 1

P0455

Evaporative emission system leak detected — large leak

P0128

Coolant thermostat below regulating temperature

P0442

Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN

Decode a VIN to confirm the transmission and build data for a specific Century. OEM

Build data

Plant, GVWR class, engine and body data for any 17-character VIN.

Recalls

Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Group 78 battery Vehicles taking 4.5 qt Engine oil filter 12731175 Engine air filter 19166106 Fuel filter 25121293 Spark plug 19301813

Reference guides

Cross-vehicle references for the kinds of data on this page.

Vehicle recalls & TSBs OBD-II trouble codes Torque specifications Maintenance schedules Fluid capacities & specs

Frequently asked

How much oil does the 1998 Century take?

4.5 qt of 5W-30 API, per the factory manual.

Does the 1998 Century have open recalls?

NHTSA lists 4 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Century get?

EPA figures are 17 city / 27 highway / 21 combined mpg.