Volvo S80
Updated SI6 engine with 3.0 litres and increased output of 224 kW. Improved turbocharger and revised ECU compared to the T2. Complex maintenance due to a tight engine bay; chain tensioner and oil pump are known service points.
Executive-class drivetrain
Refined T6 in the S80 — powerful and quiet. Premium touring comfort with genuine sporting drive.
Engine Weaknesses 6
Engines before model year 2012 had a known piston ring problem with elevated oil consumption. Volvo offered an 8-year / 100,000-mile warranty extension. Revised pistons and rings from 2012.
Symptoms: Rapidly dropping oil level, blue exhaust smoke, engine oil blackens faster than normal.
The SI6 timing chain is fundamentally robust and 'engine-life' rated. Rare but documented: chain tensioner gives up and chain slaps. Repair on this engine is very labour-intensive.
Symptoms: Rattling or chattering noise from top of engine especially cold, check engine light, P0340 fault.
The B6304T4 thermostat sticks in the closed position, especially when it has not been changed for a long time. The warm-up phase is normal, but then it fails to open and engine temperature climbs to critical levels.
Symptoms: Engine temperature rises too high after a short drive, temperature warning, poor heater output in cold weather
SI6 B6304T4 PCV diaphragm tears and produces a hissing noise. Damaged PCV increases crankcase pressure and can damage seals. Typical long-life wear item on this engine.
Symptoms: Whistling hissing noise from engine bay especially at idle, oil seeping, rough idle.
Like its predecessor the B6304T2, the B6304T4 PCV diaphragm is also a known wear item. The diaphragm tears, causes hissing noises, and allows oil vapour into the intake tract. Replacing the membrane alone is often not a lasting fix — complete box replacement recommended.
Symptoms: Hissing at idle, elevated oil consumption, oil mist on air filter hose
The B6304T4 received Volvo's revised piston rings but remains sensitive to poor oil change discipline. Neglected PCV maintenance accelerates piston ring wear. Maximum 10,000 km oil change interval.
Symptoms: Increasing oil consumption above 200,000 km, blue smoke under load, slightly cloudy oil
Vehicle Weaknesses 17
The Powershift dual-clutch gearbox (Getrag 6DCT450) jumps to neutral, jerks on acceleration and shows delayed shifts. Plastic clutch basket spacers break and require clutch replacement. Fluid change every 60,000 km is important.
The steering rack of the V70 III and S80 II develops leaks and increasing play at high mileages. A faulty steering rack costs around €2,000 to repair.
The front subframe on the V70 III and XC70 II frequently shows corrosion, which, if left untreated, affects the entire front axle assembly. On the XC70 II, the rear subframe also rusts on vehicles built before 2010.
The optional electronic self-levelling suspension on the V70 III XC models fails. Compressor or air springs need replacement; costs up to €1,600 with original Volvo parts.
The optional rear self-levelling suspension on the S80 II fails with increasing mileage. Repair costs around €1,600. Failed air springs are identifiable by the car sitting low at the rear.
A/C compressors on 2008 and 2009 models tend to leak refrigerant. Inspection requires lowering the front undertray.
The steering rack on individual S80 II MY 2007–2010 vehicles develops knocking noises when turning slowly. Test drive: turn the steering wheel from lock to lock several times. Replacement costs approx. €2,000.
The audio and navigation unit of the S80 II suffers from cold solder joints on the circuit board, leading to intermittent failures. First sporadic freezing, then total failure. Replacement costs at least €700.
The steering rack on the S80 II (mainly MY 2007–2010) produces knocking noises when turning at low speed. The cause is play in the steering rack. Repair costs around €2,000.
The rubber bushings in the S80 II front control arms harden with age and mileage. Banging over bumps and an imprecise steering feel are the result. Replacement is often combined with a wheel alignment.
The rear control arm rubber bushings on the V70 III and XC70 II typically wear from 160,000–170,000 km and cause driving noises. Also a known issue on the S80 II. Replacement is essential for precise handling.
The audio and navigation system of the V70 III and S80 II fails due to cold solder joints in the control unit. Parking sensors fail at around 170,000 km. Xenon headlights burn out between 170,000 and 200,000 km.
The BLIS blind spot warning system fails due to moisture in the wiring harness or faults in the wing mirror sensors. The warning system remains permanently active or stops responding.
The rear control arm bushings deteriorate after approximately 160,000 km or 8 years. Banging noises at the rear axle are characteristic; repair approx. €400–700.
The BLIS (Blind Spot Information System) on the S80 II triggers false alarms due to moisture ingress in the cable routing. The warning light illuminates for no real reason, unsettling drivers and reducing the assistant's usefulness.
The leather and T-Tec upholstery on the V70 III and S80 II tends to crack and split at the seat bolsters of the driver's seat. This often begins at medium mileages.
Ultrasonic parking sensors fail from around 170,000 km. Cheap no-name replacements often do not work reliably for long — original Volvo sensors are recommended.
Reports & Tests
139 owner complaints filed with NHTSA (2006–2016). Most reported: Body Structure (21), Electrical (19), Engine (19).