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1999 Oldsmobile Silhouette EXT

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1999 Silhouette EXT.

Body VANTransmission Automatic 4-spd

The 1999 Oldsmobile Silhouette EXT is a full‑size van built on the Buick SU platform, equipped with an automatic 4‑speed transmission that delivers 16/23/18 mpg EPA ratings. Its maintenance routine calls for 4.5 quarts of 5W‑30 API oil, a detail that underscores the vehicle’s moderate engine demands. With 155 owner complaints, the most common issue centered on engine and cooling components, and a total of seven recalls, the model year sits at the lower end of the Silhouette’s reliability spectrum, suggesting that prospective owners should remain vigilant about routine engine upkeep.

Model year2003 2002 2001 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 economy16/23/18 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 Note the factory front wiper blades and serpentine belt are now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known.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 sizeP215-70R15OEM · verified

Wheel / rim6-JJ inOEM · verified

OE service part numbers OEM · verified

Engine oil filter	12731175
Engine air filter	19166106
Fuel filter	10290491
Spark plug	19301813
Front wiper blades	10329206 discontinued · alt 10329207
Serpentine belt	19172683 discontinued
Thermostat	24507563 alt 10226107

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

Transmission

Automatic 4-spd

Dimensions & weight NHTSA vPIC

Overall length	187.4 in
Overall width	72 in
Overall height	67.3 in
Wheelbase	112.2 in
Curb weight	3746 lb
Track (front / rear)	61.4 / 63.4 in
Weight distribution (front / rear)	58/42

Ratings & economy EPA / vPIC

EPA city / highway / combined	16 / 23 / 18 mpg
Drivetrain	Front-Wheel Drive
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 oil drain plug to 18.0 ft-lbs. The firing order is 1-2-3-4-5-6. Note the cylinder-head bolts finish on a torque angle (torque-to-yield) — they stretch permanently and should be replaced, not reused, during any head service.

Lubricants & capacities

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

Engine torques

Crankshaft Pulley and/or Damper Bolts	76 ft-lbs
Intake Manifold to Engine Bolts	Upper: 18 ft-lbs
Exhaust Manifold to Cylinder Head Bolts	12 ft-lbs
Engine Oil Pan Drain Plug	18.0 ft-lbs
Engine Valve Cover Bolts	7.4 ft-lbs

Chassis torques

Lug Nuts	100 ft-lbs
Front Wheel Hub	118 ft-lbs

Ignition

Cylinder Firing Order	1-2-3-4-5-6
Spark Plug Manufacturer	AC Delco
Spark Plug Type	41-940
Spark Plug Gap	0.060 in
Spark Plug Torque	11.0 ft-lbs

Battery & A/C

Refrigerant	R134a
Refrigerant Capacity	Front A/C only, 2.00; front and rear A/C, 2.90. lbs
Oil Group	PAG
Oil Type	150
Standard BCI Group Number	78
Standard BCI Cranking Performance	600 cca

Service checks

Pressure Test	20 psi
Radiator Cap Pressure Relief	15 psi
Thermostat Opening Temperature	188-206 °F
Injector Primary Resistance	11.4-12.6 @ 50-95 degreesF ohms
Engine Compression	100
Engine Compression	100 Minimum psi
Engine Oil Pressure	60 psi
Engine Oil Pressure RPM	1850 rpm

Brakes

Brake Application	WITH REAR DISC / WITH STANDARD
Torque Caliper to Bracket	33 ft-lbs / 63 ft-lbs
Torque to Knuckle	92 ft-lbs / 137 ft-lbs
Minimum Pad Thickness	Front: 0.030; Rear: 0.030 specification
Brake Application	WITH REAR DISC / WITH STANDARD
Rotor Max Parallel Variation	0.0005 in
Rotor Runout Limit	0.003 in
Rotor Nominal Thickness From	0.433 in / 1.27 in

Multi-step torque procedures OEM · verified

Cylinder Head — tightening sequence 2 stages

1	44 ft. lbs.	44 ft. lbs
2	90 degrees.	90 degrees

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 every 7,500 mi. The big-interval services (every 7,500 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	Body Latches, Locks & Hinges (lubricate) · Brake System (inspect) · Engine Coolant System (leak inspection) · Engine Oil (drain & refill) · Engine Oil Filter (replace) · Parking Brake Cable (lubricate)
Every 15,000 mi	Cabin Air Filter (replace)
Every 30,000 mi	Engine Air Filter Element (replace)
Every 60,000 mi	Accessory Drive Belt (inspect) · Fuel Line (inspect) · Fuel Tank (inspect) · Fuel Tank Filler Cap (inspect)
Every 100,000 mi	Spark Plug Wires (inspect) · Spark Plugs (replace)

Reliability & federal safety record

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

Owner complaints about the 1999 Oldsmobile Silhouette EXT lead in one area — the engine & engine cooling, 44 of 155 reports (28%), well ahead of the next concern. None of this vehicle's 7 recall campaigns target the engine & engine cooling, so those reports read as owner-reported wear-and-tear rather than an acknowledged defect. 9 of the reports describe a crash and 4 a fire — a small share of the total, but worth weighing against the engine & engine cooling pattern above. These are tallies of what owners actually reported to the federal government, not an editorial score — and higher-selling models naturally rack up more reports.

Open recalls

NHTSA campaigns

Service bulletins

Manufacturer communications

ODI investigations

Office of Defects Investigation

155

Owner complaints

9 involved a crash · 4 a fire

NHTSA crash-test rating federal NCAP · out of 5 stars

Rollover★★★★★

Owner complaints filed with NHTSA, by component

All 155 complaints on record, top 8 components.

Engine & Engine Cooling44

Power Train13

Structure12

Air Bags10

Latches/Locks/Linkages9

Seat Belts6

Fuel System, Gasoline5

Visibility5

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 7 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…

08E050000Exterior Lighting:HeadlightsReported 11/08/2008

K2 MOTOR IS RECALLING 1,921 AFTERMARKET HEADLAMPS OF VARIOUS MODELS SOLD FOR USE ON THE ABOVE LISTED VEHICLES. THESE HEADLAMPS ARE MISSING THE AMBER SIDE REFLEX REFLECTOR WHICH FAILS TO CONFORM WITH THE REQUIREMENTS OF… Remedy: K2 MOTOR WILL NOTIFY OWNERS AND OFFER A FULL REFUND. THE RECALL BEGAN ON DECEMEBER 17, 2008. OWNERS MAY CONTACT K2 MOTOR AT 1-909-839-2992.

Technical service bulletins NHTSA · verified

Showing 5 of 92 bulletins on record with NHTSA.

Bulletin	Date	Component	Summary
17-NA-073	2023-02-21	Equipment	This warranty administration bulletin provides information regarding the field action…
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…
17NA073	2019-09-18	Equipment	This warranty administration bulletin provides information regarding the field action…

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 Silhouette EXT. 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 10290491 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 1999 Silhouette EXT take?

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

Does the 1999 Silhouette EXT have open recalls?

NHTSA lists 7 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Silhouette EXT get?

EPA figures are 16 city / 23 highway / 18 combined mpg.