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986.2 · 2003–2004

2004 Porsche Boxster

2.7 L flat 6 · RWD · Roadster · water-cooled

Power
228hp
Torque
192lb-ft
0–60
6.2s
Weight
2,822lb
lb / hp
12.4
Displacement
2.7L

Specification

US-market 2004
Power 228 hp
201 493
Weight 2,822 lb
2,778 3,212
Weight to power 12.4 lb/hp
6.5 lower is quicker 13.8

Where this car sits against every Boxster in the catalog.

Engine
Engine code M96.23
Layout flat 6, water-cooled
Displacement 2.7 L
Aspiration Naturally aspirated
Power 228 hp @ 6,300 rpm
Torque 192 lb-ft @ 4,700 rpm
Redline 7,200 rpm
Specific output 84 hp / L
Chassis & body
Drivetrain Rear-wheel drive
Body styles Roadster
Transmissions 5-speed Manual · 5-speed Tiptronic
Curb weight 2,822 lb
Wheelbase 95.2 in
Length 171.0 in
Width 70.1 in
Height 50.8 in
Performance & market
0–60 mph 6.2 s
Top speed 155 mph
Weight to power 12.4 lb / hp
MSRP when new $42,600 base

About the 2004 Boxster

2004Final 986 model year before the 987 arrives.

BoxsterFacelift: glass rear window at last, revised nose and lights, better interior plastics, 228 hp. The one to have if you are buying a base car.

Known issues

8 Specific to the Boxster

IMS bearing failure

Critical $1,600–$3,200
Affects

All 986. The bearing design changed through the run, which determines whether a retrofit is even possible.

What happens

The intermediate shaft bearing loses its seal, runs dry and disintegrates. Debris circulates, the shaft loses position, and the valvetrain meets the pistons. On a car worth what a 986 is worth, that is usually the end of it.

Symptoms
  • Metal flake or glitter in the oil filter
  • Rumble from behind the seats at idle
  • Oil weeping from the IMS flange
  • Frequently no warning at all
What to do

Retrofit during a clutch job, when the transmission is already out. Dual-row bearings (roughly 1997–1999) are the most robust from the factory; single-row cars are the usual retrofit candidates. Identify which bearing the engine has before buying parts.

Parts for this job

Blocked drains and water ingress

Critical $0–$4,000
Affects

All 986, and the single most under-appreciated killer of cheap ones.

What happens

The convertible top has drains at each rear corner and the cabin air intake has its own. Leaves and pine needles block them, water backs up, and it goes into the footwells and the sills. Sitting water reaches the electronics, rots the floors from underneath, and drowns the immobiliser and relay panel. A car that smells damp inside is telling you something expensive.

Symptoms
  • Damp or wet carpets, especially the passenger footwell
  • Musty smell with the top up
  • Electrical faults that come and go with the weather
  • Water audibly sloshing in the sills over bumps
What to do

Clear all four drains at least annually — it is a ten-minute job with a length of trimmer line. Lift the carpets and check for staining before you buy. Rusty floors on a mid-engine Porsche are a walk-away.

Parts for this job

Cylinder bore scoring

Critical $10,000–$20,000
Affects

M96 engines, more commonly reported on the 3.2 S than the smaller base engines.

What happens

The cylinder liner surface degrades and the piston skirt scores the bore. Oil consumption climbs, compression falls, and the repair costs more than the car.

Symptoms
  • Oil consumption past roughly a quart per 1,000 miles
  • Cold-start ticking that fades with heat
  • Smoke on start or overrun
  • Uneven compression and leak-down
What to do

No preventive fix. Borescope every cylinder before purchase. On a car in this price bracket, the inspection genuinely decides whether it is worth buying at all.

Convertible top transmission and cable failure

Major $400–$1,800
Affects

All 986.

What happens

The top is driven by cables and a transmission that fray and seize with age. The roof jams part-open, which on a roadster is not a defect you can defer.

Symptoms
  • Top stopping partway through its cycle
  • Grinding or clicking from the rear quarters
  • Roof sitting unevenly or not latching
  • Motor running with nothing moving
What to do

Cable and transmission repair kits are available and far cheaper than a shop diagnosing it from first principles. Cycle the top fully several times at inspection — this is the fastest way to find a deferred repair.

Parts for this job

Air–oil separator failure

Major $500–$1,000
Affects

All 986.

What happens

The separator diaphragm tears and the engine ingests oil through the intake.

Symptoms
  • Dense white smoke at start or under load
  • Rough idle
  • Oil consumption with no external leak
What to do

Replace the AOS. Cheap relative to the panic its smoke causes — many 986s are sold cheaply by owners who assumed the engine was finished.

Parts for this job

Coolant expansion tank cracking

Major $250–$600
Affects

All 986.

What happens

The plastic tank goes brittle with heat cycles and splits, often at the seam, dumping coolant quickly. Overheating an M96 is how a cheap problem becomes an engine.

Symptoms
  • Coolant loss with no visible hose leak
  • Low coolant warning
  • Sweet smell after a drive
  • Residue around the tank seam
What to do

Replace the tank with the cap and level sensor. Considered a maintenance item rather than a repair on a car this age.

Parts for this job

Ignition switch failure

Minor $200–$550
Affects

All 986, subject of a service campaign.

What happens

The electrical portion of the switch fails and the car will not crank, or will not shut off.

Symptoms
  • No crank, no dash lights
  • Key turns with no response
  • Engine will not stop with the key
What to do

Replace the switch — cheap part, moderate labour.

Parts for this job

Radiator debris and corrosion

Minor $700–$1,800
Affects

All 986.

What happens

The front radiators sit low and fill with leaves and grit that hold moisture against the cores until they corrode and leak.

Symptoms
  • Slow coolant loss
  • Weak air conditioning
  • Debris visible through the bumper ducts
What to do

Fit grille screens and clear the ducts annually. Replace radiators and condensers as a set once they weep.

Parts for this job

Service intervals

10
Item Interval
Engine oil and filter 5,000 mi or annually
Convertible top drains Annually, at minimum
Spark plugs 30,000–40,000 mi
Serpentine belt 4 years / 40,000 mi
Coolant 4 years
Brake fluid 2 years
Clutch 60,000–100,000 mi
Transmission fluid 60,000 mi
Top mechanism lubrication Annually
Suspension bushings and mounts 80,000+ mi

What fits this car

36 Sizes, capacities and part specs

The answers you need when something has already failed — bulb sizes by position, wiper lengths, battery group, fluid specs and capacities. Sizes are for US-spec cars and are a starting point: options and mid-year changes move them, so check against your own car and its VIN before ordering.

Bulbs

11 The 986 shares its headlight unit with the 996, so bulbs interchange.
Low beam — halogen H7 55W Shop →
Low beam — Litronic xenon D2S 35W Factory option. Never fit an HID kit into a halogen housing. Shop →
High beam H7 55W Shop →
Front turn signal PY21W Amber. Shop →
Front position / parking W5W Shop →
Fog light H3 55W Shop →
Brake / tail P21/5W Shop →
Rear turn signal PY21W Shop →
Reverse P21W Shop →
Licence plate W5W Shop →
Side marker W5W Shop →

Wiper blades

2
Driver side 24 in Shop →
Passenger side 24 in Shop →

Battery

3
Group size Group 48 (H6) Shop →
Location Front luggage compartment —
Minimum cold cranking amps 600 CCA —

Fluids and capacities

8
Engine oil — capacity (2.5 / 2.7) 7.9 qt with filter —
Engine oil — specification 0W-40, Porsche A40 approved Shop →
Coolant — capacity 21 qt Long runs to the front radiators, so bleeding it properly matters. —
Coolant — specification Porsche pink G40, phosphate-free Shop →
Brake fluid DOT 4, low viscosity Shop →
Manual transmission 2.6 qt, 75W-90 GL-5 Shop →
Power steering Pentosin CHF 11S Shop →
Fuel tank 15.3 gal —

Wheels and tyres

9
Bolt pattern 5 x 130 mm
Centre bore 71.6 mm
Lug bolt thread M14 x 1.5
Tyre size — 16 in front 205/55 ZR16
Tyre size — 16 in rear 225/50 ZR16
Tyre size — 17 in front 205/50 ZR17
Tyre size — 17 in rear 255/40 ZR17
Tyre size — 18 in front 225/40 ZR18
Tyre size — 18 in rear 265/35 ZR18

Torque values

3 Safety-relevant. Verify against factory documentation before relying on these.
Wheel lug bolts 96 lb-ft (130 Nm) Star pattern, on the ground, calibrated wrench.
Engine oil drain plug 37 lb-ft (50 Nm) New sealing washer every time.
Oil filter housing cap 18 lb-ft (25 Nm)

Fitment for the 2004 986.2 Boxster. Torque values in particular are safety-relevant — verify against factory documentation rather than relying on this page alone.

Buying guide

8
  1. 01

    Lift the carpets before you look at anything else

    Damp footwells, staining, or a musty smell mean blocked drains and possibly rotten floors. This is the fastest way to reject a bad 986, and it costs nothing to check.

  2. 02

    Borescope every cylinder

    On a car worth $10,000–25,000, a scored bore is a total loss. The inspection is a small fraction of the purchase price and it is the difference between a bargain and a boat anchor.

  3. 03

    Cycle the top, several times, fully

    Up, down, up, down. Listen for grinding and watch for hesitation. A jammed top is one of the most common deferred repairs on these cars and sellers know to leave it closed.

  4. 04

    Cut the oil filter open

    Ferrous glitter in the pleats is a walk-away. Bring a cutter to the inspection or ask the shop to do it while you watch.

  5. 05

    Prefer a 2003 or later if you can

    Glass rear window, better interior plastics, more power and a facelifted nose. The improvement per dollar over a 2002 is larger than the price gap.

  6. 06

    Treat the IMS history honestly

    A documented retrofit with an invoice and a part number adds real value. "The previous owner said it was done" adds nothing. Identify which bearing the engine has before planning the work.

  7. 07

    Buy the maintained one, not the pretty one

    Cheap 986s are cheap because the deferred work exceeds the car’s value. A well-kept example at a higher price is almost always the less expensive car to own.

  8. 08

    Manual over Tiptronic, and it is not close

    The 5-speed Tiptronic blunts a car whose entire appeal is immediacy. It also costs real money at resale.

Parts and gear

23 Chosen for this car, not for the commission

What a Boxster actually costs to keep, grouped by why you would buy it. Prices are typical US parts-only figures — labour is separate, and the DIY note says whether that matters. Where a link earns us a commission it costs you nothing and never changes what appears here.

Parts that fix a known problem on this car

6 Each one maps to an issue above
  • Engine $700–$1,900

    IMS bearing retrofit kit

    The fix for the failure above, and only sensible to fit while the transmission is out for a clutch. Identify whether the engine has the dual-row or single-row bearing before ordering — they are not interchangeable.

    FCP Euro → Shop job
  • Top $150–$500

    Convertible top cable and transmission kit

    Replacement drive cables and transmission parts for a roof that jams part-open. Far cheaper than a shop working it out from scratch, and this is the failure most likely to be waiting on a cheap 986.

    FCP Euro → DIY or shop
  • Engine $180–$400

    Air–oil separator

    The part behind the terrifying smoke. Cheap enough to fit on spec, and the reason a lot of perfectly healthy 986s change hands for scrap money.

    FCP Euro → DIY or shop
  • Cooling $120–$280

    Coolant expansion tank

    Nearly every 986 needs one. Replace the cap and level sensor at the same time — overheating an M96 turns a $200 part into an engine.

    FCP Euro → DIY or shop
  • Cooling $450–$1,000

    Radiator and condenser pair

    Once the cores weep there is no repair. Do both sides and the condensers behind them while the bumper is off.

    FCP Euro → Shop job
  • Electrical $40–$100

    Ignition switch

    A cheap part behind moderate labour, and a common reason a 986 simply refuses to start one morning.

    FCP Euro → DIY or shop

Worth doing before it fails

7 Cheaper than the repair it avoids
  • Cooling $80–$190

    Radiator grille screens

    The reason those radiators rot. Mesh in the ducts, fitted in an afternoon, guarding a repair that costs ten times as much.

    Shop this → DIY
  • Body $10–$40

    Drain cleaning kit and trimmer line

    The highest return on investment on this entire page. A few dollars of line and ten minutes a year prevents the flooded footwells, dead electronics and rotten floors that kill cheap Boxsters.

    Shop this → DIY
  • Engine $110–$210

    Low-temperature thermostat

    Opens earlier and holds the engine cooler in traffic. Widely fitted by owners who would rather have thermal margin than an argument about whether it prevents bore scoring.

    Shop this → DIY or shop
  • Engine $25–$60

    Magnetic drain plug

    Catches ferrous debris where you will see it at every oil change. With a cut-open filter it is the whole early-warning system for an M96.

    Shop this → DIY
  • Ignition $230–$450

    Coil pack and spark plug set

    Six of each. Coils fail on age rather than mileage, so doing them together turns a future misfire into a planned afternoon.

    Shop this → DIY
  • Chassis $150–$400

    Engine and transmission mount set

    Twenty-five-year-old mounts let the drivetrain move, which the driver reads as vibration and slop rather than as a worn part. Cheap, and it sharpens the car noticeably.

    FCP Euro → DIY or shop
  • Chassis $280–$700

    Control arm and bushing kit

    Tired bushings quietly erase the steering precision that is the entire reason to own a mid-engine car. The most transformative suspension spend on a high-mileage 986.

    FCP Euro → Shop job

Consumables you will rebuy

5 Ordinary running costs
  • Fluids $65–$130

    Porsche-approved engine oil

    The M96 is specific about weight and additive package, and this is not the engine to economise on. Around eight quarts a change on a shortened interval.

    Shop this → DIY
  • Fluids $15–$45

    Oil filter and hardware

    Bought with every change, and the thing you cut open afterwards. Get the crush washers in the same order.

    Shop this → DIY
  • Fluids $30–$80

    Porsche-spec coolant

    The correct pink specification. Mixing chemistries in an aluminium and plastic cooling system is a slow and expensive mistake.

    Shop this → DIY
  • Fluids $15–$60

    Brake fluid

    Two-year replacement. On a light car with good brakes, fresh fluid is most of what you need.

    Shop this → DIY
  • Service $25–$70

    Cabin and engine air filters

    Ten-minute jobs that shops bill properly for. Check the cabin filter drain while you have the box open.

    Shop this → DIY

Tools worth owning

5 Bought once, used for years
  • Diagnostics $250–$1,000

    Porsche-specific diagnostic interface

    A generic reader sees almost nothing of what a 986 stores. A Porsche-specific tool reads every module and clears the airbag and immobiliser faults that damp carpets tend to cause.

    Shop this → DIY
  • Inspection $50–$220

    Borescope camera

    Check the cylinder walls through the plug holes yourself. On a car this cheap, it decides whether an inspection is even worth paying for.

    Shop this → DIY
  • Inspection $30–$80

    Oil filter cutter

    Opens the filter so you can spread the pleats and look for metal. Cheapest early warning that exists for this engine.

    Shop this → DIY
  • Lifting $150–$400

    Low-profile jack and jack pads

    A standard trolley jack will not clear the sill, and the jack points crush without a proper puck.

    Shop this → DIY
  • Storage $50–$130

    Battery tender

    These sit more than they are driven, and a flat battery on a 986 scrambles the alarm and immobiliser as well as stranding it.

    Shop this → DIY