Volvo XC90
Naturally-aspirated short inline-six with 3.2 litres, 175 kW, and smooth running. Developed for Volvo flagship models as a refined alternative to the turbocharged engine. Chain drive with known chain tensioner weaknesses at higher mileages.
Luxury without rush
175 kW in the heavy XC90 — adequate for relaxed drives, no engine for those in a hurry.
Engine Weaknesses 7
The READ (Rear Engine Auxiliary Drive) on early B6324S engines uses needle bearings instead of ball bearings. These bearings can seize with inadequate lubrication. Switched to ball bearings from 2011 (B6324S5).
Symptoms: Loud rattling or grinding from the rear of the engine, oil pressure loss, MIL light, engine noise under load.
Before MY2011, the READ unit (Rear Engine Ancillary Drive) uses needle roller bearings that can fail prematurely under splash lubrication. Typical symptom: squealing/grinding from the engine bay. Complex removal with special tooling required.
Symptoms: Grinding or rumbling from the right-hand side of the engine bay, especially on cold start; progressively louder
Technical service bulletins document oil leaks at the B6324S camshaft end plugs. Oil seeps from the side of the cylinder head. Volvo has issued a repair procedure.
Symptoms: Oil leak at the side of the cylinder head, oil smell after driving, engine oil loss with no visible underbody source.
Two of the four catalytic converters are integrated directly into the exhaust manifold. If they fail, the manifold must be replaced as an assembly — an extremely expensive part. 8 hours labour due to poor accessibility.
Symptoms: Check engine light, elevated emissions, typical sulphur smell from exhaust, power loss
The 6-cylinder occasionally suffers coolant loss through ageing hoses and failed thermostats. At high mileages the cooling system should be serviced as a unit to prevent overheating damage.
Symptoms: Rising coolant temperature, coolant loss without visible leak, occasional heater failure in winter
The vacuum pump for the brake booster can leak and lose oil. Aftermarket repair kits are inexpensive, but the leak point only becomes visible after cleaning.
Symptoms: Oil leak at the lower rear of the engine, oil loss without obvious source, occasionally reduced brake assist.
Older B6324S engines tend towards slight oil loss through worn valve stem seals at higher mileages. More common on early production years. Consumption usually below 0.5 L/1,000 km.
Symptoms: Blue smoke at start-up or on overrun, slightly dropping oil level without visible external leaks
Vehicle Weaknesses 7
The Aisin Warner AW55-50/51SN gearbox in the XC90 I is regarded as its biggest weakness: from 100,000 km it shifts harshly and with unusually long gear-change intervals. Valve body faults often require a complete transmission overhaul.
The Haldex all-wheel drive system on early XC90 models (pre-2007) shows wear at the coupling and differential. If the damage is not corrected, the entire drivetrain can fail.
The optional air suspension compressor on the XC90 I overheats or freezes in sub-zero temperatures. Moisture in the compressor and pipes freezes at around -5°C and blows the fuse. Repair at the dealer around €1,600.
On the XC90 I, tie rod ends (especially outer), ball joints and control arms at the front axle wear out. This leads to wheel misalignment and heavy one-sided tyre wear. Replace early to avoid consequential damage.
The front subframe behind the radiator is known for corrosion, especially on vehicles from road-salt regions. Visible rust on the subframe requires treatment and sealing (€600+).
The nav and audio system of the XC90 I fails due to cold solder joints in the RTI control unit — a known Volvo issue of this era. Replacement units cost over €700; professional re-soldering is cheaper.
Rear control arm bushings deteriorate after approximately 150,000 km. Knocking over bumps and unstable handling are the result. Replacement costs €500–900.
Reports & Tests
957 owner complaints filed with NHTSA (2002–2014). Most reported: Electrical (276), Powertrain (275), Engine (85).