1996-2004 (first generation) · 2.7L M96 flat-six petrol (220-228 hp)
Porsche's first mid-engine roadster since the 914. An iconic driver's car and incredible value, but demands respect for its known weaknesses. The 2.7L engine is one of the more reliable M96 variants with lower bore scoring risk than larger engines. Main concerns: IMS bearing failure (5-8% of cars, catastrophic when it happens), rear main seal leaks (very common but usually minor), coolant expansion tank failures, and convertible top issues. Pre-2000 models had dual-row IMS bearings (more reliable), while 2000-2004 used single-row bearings (higher failure rate). The 2003-2004 models are the most refined. No timing belt - uses chain, but tensioner pads wear over time.
Expected Annual Maintenance Costs
€1,200 - €2,000/year
15,000 km/year
Fixed costs
€800-1,400
Risk buffer
€400-1,200
What Can Break
bars = likelihood
IMS bearing failure€2,500 - €20,000
Sealed intermediate shaft bearing can fail catastrophically, destroying engine · more· less
The M96 engine's Achilles heel. The IMS bearing supports the intermediate shaft that drives the camshafts. When it fails, metal debris circulates through the engine causing catastrophic damage requiring rebuild or replacement. Failure rate: dual-row bearing (1997-1999) approximately 1%, single-row bearing (2000-2004) approximately 5-8%. Preventive replacement costs €2,500-3,500 and should be done with clutch replacement. If bearing fails, engine rebuild starts at €15,000-20,000, replacement can reach €30,000+. Warning signs: metallic debris in oil filter, oil leak at rear of engine, knocking sounds. LN Engineering and other specialists offer upgraded bearings with better lubrication. Most failures occur between 40,000-100,000 km, though can happen at any mileage. 2000-2001 cars with dual-row bearings are safer than 2002-2004 single-row models.
Rear main seal (RMS) leak€1,200 - €2,500
Oil leak from crankshaft seal, common on M96 engines · more· less
Very common issue on 986 Boxsters. The seal where the crankshaft exits the engine tends to leak oil. Usually presents as minor oil weeping rather than major leak, but can contaminate clutch if severe. The seal itself costs under €50, but requires complete gearbox removal to access (8-12 hours labor). Total cost €1,200-2,500 depending on shop rates. Porsche redesigned the seal multiple times - current PTFE version (part number 0PB-105-249) is most reliable. If leak is minor, many specialists recommend waiting until clutch replacement is needed, then doing both jobs together. Always replace RMS when doing IMS bearing or clutch work since gearbox is already out. Use genuine Porsche PTFE seal only. Can be caused by mis-machined crankcase from factory or using older seal designs.
Coolant expansion tank failure€300 - €600
Plastic tank in trunk cracks and leaks, extremely common on aging cars · more· less
One of the most common 986 failures. The plastic coolant expansion tank located in the trunk becomes brittle over time and develops cracks, typically at the bottom or where hoses connect. Six different hoses connect to the tank, creating multiple failure points. Symptoms: coolant puddle in trunk under carpet, coolant loss, overheating. The tank and hoses cost €150-250, labor 2-3 hours. Early cars also had problematic coolant caps that failed under pressure - updated cap needed (verify correct part number). If you see a 986 with original tank and it's over 15 years old, replacement is not "if" but "when." This is an easy DIY job with basic tools. Failure to address can lead to engine overheating and serious damage. Also check all coolant hoses as they age poorly.
Air-oil separator (AOS) failure€600 - €1,400
Diaphragm fails, allowing oil into intake system · more· less
The AOS separates oil from crankcase vapors. When it fails, oil gets sucked into the intake manifold and burned, causing thick white/blue smoke from exhaust (especially on cold start), excessive oil consumption, rough idle, misfires, and check engine light. Can also cause high-pitched whistle under load. In severe cases, can hydraulically lock engine with oil (catastrophic). Typically fails between 60,000-100,000 km. Part costs €350-500, labor 3-5 hours. Use only genuine Porsche parts - aftermarket AOS units often fail prematurely. Should be treated as maintenance item and replaced every 6 years or 75,000 km preventively. When replacing, also replace all AOS vent hoses and lines. Early warning sign: excessive oil consumption without visible leaks. Check for oil residue in intake manifold or on air filter.
Water pump failure€800 - €1,700
Bearing failure or impeller disintegration, typically 70,000-100,000 km · more· less
The water pump is located behind the driver's seat in the mid-engine layout. Common failure modes: bearing noise (audible knocking from behind driver seat), impeller vanes breaking off and circulating through cooling system, leaks. Symptoms include coolant warning light, engine overheating, or poor cabin heating. The pump costs €200-400, but labor is 4-6 hours due to difficult access requiring removal of seat and interior trim panels. Some specialists charge €800-1,700 total depending on labor rates. Most 986 owners replace the pump at least once during ownership. When replacing, also inspect all coolant hoses and consider replacing thermostat at same time since you're already in there. Failure can cause severe overheating damage if not addressed immediately.
Convertible top issues€500 - €3,500
Cables snap, gears wear, microswitches fail, plastic windows crack · more· less
Multiple failure points in the complex convertible top mechanism. Common issues: (1) Transmission gear failure - plastic gears in the mechanism crack/strip, causing top to operate unevenly or not at all. One side gear replacement €100-200 parts, or dealer quotes €2,500-3,500 for full motor/transmission replacement. (2) Tension cables snap - cables that pull the top into position break, especially on high-mileage cars. (3) Microswitches fail - prevent top operation, need diagnosis to find which of multiple switches is faulty. (4) Plastic rear windows (pre-2003) crack and become hazy over time - full top replacement €1,500-2,500 installed. 2003+ glass windows are much better. (5) Side beading doesn't seal properly, letting in water and wind noise - often just needs proper seating in channel. Many top issues are DIY-fixable for under €100 if you identify the specific problem (often just a cracked gear).
HVAC foam deterioration€200 - €800
Blend door foam disintegrates, spewing black foam particles from vents · more· less
Affects very high percentage of 986 cars over 15 years old. The foam on the HVAC blend doors breaks down and becomes tiny black particles that shoot out of vents when the blower runs. Also causes loss of heating ability as degraded foam creates holes allowing cold air to bypass. Symptoms unmistakable: black foam debris from vents, inability to heat cabin properly. Repair requires removing blend doors and re-foaming them. DIY kits available for €50-150 with instructions - takes 2-4 hours for experienced DIYer using cowl access method. Professional repair €400-800. Removing entire dash/HVAC box is prohibitively expensive (€2,000+ labor). This is almost inevitable on all 986s eventually. Not safety-critical but very annoying. Some owners live with it, others fix it themselves. The only permanent solution is re-foaming the doors - temporary fixes don't work.
The M96 5-chain engine uses hydraulic tensioners and wear pads (guides) to keep timing chains tight. Over time, tensioner release valve weakens allowing oil pressure to bleed overnight, and the wear pads deteriorate. Main symptom: rattling noise on cold start lasting 1-30 seconds as tensioner pumps back up. Typically occurs 60,000-100,000 km. Tensioners themselves are easy to replace (few hours labor), but if guides/pads are worn, requires engine-out service similar to IMS bearing job. If you hear persistent rattle (more than few seconds), the chain may have stretched and guides worn - full replacement of chains, guides, tensioners, and sprockets needed, costing €2,500-4,000. Porsche has updated tensioner parts. This issue is less severe than IMS bearing but should not be ignored - chain skip can cause valve/piston contact and destroy engine. Early 1997-2002 engines more susceptible.
Door lock microswitch/window regulator failure€150 - €800
Window won't drop when opening door, or regulator cables stretch · more· less
Two common door issues: (1) Microswitches fail - there are 7 microswitches per door (inside handle, outside handle, 5 in lock mechanism). When they fail, window won't automatically drop when door opens, or door won't lock/unlock. Diagnosis needed to identify which switch. Switches cost €20-50 each, labor 1-2 hours per door. Total €150-400 per door. Sometimes cleaned with contact cleaner, but usually need replacement. (2) Window regulator cables stretch over time, causing window to move when you pull on it. Can re-tension cables (DIY for €10 in cable ties) or replace entire regulator mechanism (€300-800 with labor). Window regulators are common failure on 20+ year old cars. Both issues are annoying but not safety-critical. Many owners DIY these repairs successfully.
MAF sensor failure€400 - €1,000
Mass airflow sensor degrades, causing rough idle and poor performance · more· less
The MAF sensor measures incoming air for fuel mixture calculation. When it fails: rough idle, poor fuel economy, black smoke, hesitation, surging, hard starting, check engine light. Most common between 100,000-125,000 km but can fail earlier if damaged during air filter service or contaminated by over-oiled washable filters. The sensor costs €300-600 (genuine Bosch), labor 0.5-1 hour. Total €400-1,000 depending on whether you use dealer or independent shop. DIY replacement is easy - usually just a clamp or screw and electrical connector. Important: MAF sensors are model-year specific with different calibrations - 2000 was crossover year, so verify exact part number for your car. Consider replacing every 60,000-90,000 km preventively. Cleaning MAF sensors can provide temporary improvement but replacement is permanent fix.
Affordable to maintain if you catch issues early
The 986 Boxster is generally reliable when properly maintained, with an MOT pass rate of 78% (above average for age). The 2.7L engine is one of the better M96 variants with lower bore scoring risk than larger engines. IMS bearing failure is the big scary issue, but affects under 10% of cars and is preventable. Most other issues are predictable wear items. Budget-conscious ownership requires DIY skills or a good independent Porsche specialist. Well-maintained examples with IMS bearing already addressed make excellent driver's cars. The 2003-2004 models with glass rear window are the most refined first-gen Boxsters.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete service records essential, especially oil changes every 5,000-7,500 km (not the 15,000-20,000 km Porsche originally recommended). Look for IMS bearing replacement documentation.
Cold start inspection
CRITICAL: Visit car completely cold. Listen for timing chain rattle in first 30 seconds. Check oil level when cold if possible. Look for smoke from exhaust on cold start (indicates AOS failure).
Test drive
Minimum 30 minutes including varied driving. Get engine and gearbox fully warm. Listen for any unusual noises. Check all electrical functions. Test convertible top operation multiple times.
Professional PPI
Always get pre-purchase inspection from Porsche specialist. They can perform leak-down test, inspect IMS bearing area, check for bore scoring. Cost €200-400 but can save you €20,000+.
Specific for this vehicle
Check for IMS bearing replacement or upgrade
Ask if IMS bearing has been replaced with upgraded unit (LN Engineering or similar). If not, this is your biggest financial risk. Look for oil leak at rear of engine bell housing - can indicate IMS or RMS issue.
Inspect coolant expansion tank and all hoses
Open trunk, remove carpet, check coolant tank for cracks (especially bottom side and hose connections). Original tank on 15+ year old car is ticking time bomb. Check all six hose connections. Look for coolant stains.
Listen for timing chain rattle on cold start
With engine completely cold, listen carefully during first 30 seconds after start. Brief rattle (under 5 seconds) is acceptable. Persistent rattle indicates worn tensioners/guides needing replacement.
Check for oil leaks - especially RMS
Look at engine/gearbox junction for oil seepage. Minor RMS leak is very common and not critical if small. Also check for oil around AOS, valve covers, and engine case seams.
Test for AOS failure symptoms
Watch for smoke from exhaust on cold start. Ask owner about oil consumption. Check engine oil level. Look for oil residue in intake manifold or on air filter (requires removing intake).
Verify convertible top operation
Operate top 3-4 times completely. Listen for unusual grinding noises. Ensure both sides move evenly. Check plastic rear window for cracks/haziness (pre-2003) or glass condition (2003+). Inspect top fabric for tears and seam integrity.
Check water pump operation
After test drive, check coolant temperature remains stable. Listen from inside cabin behind driver seat for pump bearing noise (knocking sound). Check coolant level doesn't drop.
Test HVAC system thoroughly
Turn on blower fan at all speeds and check vents. If you see black foam particles, blend doors have deteriorated (very common, not critical). Test heating function - should produce hot air within a few minutes.
Inspect for water ingress
Check carpets in footwells and trunk for dampness or water staining. Check door drainage - have seller put top in service position to access body drains on each side. Clogged drains cause water damage to electronics.
Test door lock and window operation
Windows should automatically drop slightly when opening door. If not, microswitches likely failed. Open/close each door with inside and outside handles. Test central locking with key fob. Pull window up/down by hand to check for regulator cable slack.
Check suspension bushings and components
Lower arm bushings and trailing arm rose joints wear every 40,000-60,000 km. Listen for creaking over bumps. Check for uneven tire wear. Look for cracked or broken coil springs.
Verify model year for IMS bearing type
1997-1999 have more reliable dual-row IMS bearing. 2000-2004 have higher-risk single-row bearing. Know what you're buying. 2003-2004 are most refined with glass window but still have single-row IMS.
PTFE crankshaft seals on replacement enginesTSB 1359 (Oct 2005)
Clutch pedal position issuesTSB 105 (Sep 2005)
Various year-specific recallsCheck VIN at recall.porsche.com
Use Porsche's official VIN lookup tool at recall.porsche.com to check for any open recalls on your specific vehicle. Also check 986FAQ.com for comprehensive list of technical service bulletins. While TSBs don't require free repair like recalls, they document known issues and solutions.
Warranty Status
Factory warranty (2 years)Expired on all 986 models
Porsche Classic ProgrammeAll 986 models now eligible
Extended warranty optionsLimited availability for 20+ year old cars
All 986 Boxsters are now outside their original factory warranty. However, all 986 models are now officially included in Porsche's Classic Programme, which can help with parts availability and may provide insurance benefits. Extended warranty coverage for cars this age is limited and often excludes critical items like the IMS bearing. Most owners self-insure by budgeting for potential repairs.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.