Volvo S80

The GM automatic gearbox used in the XC90 T6 was not originally designed for the full torque of the B6294T. Gearbox failures on early 2003–2005 models are documented.

Symptoms: Shifting problems, gearbox slips, gear selection refused, gearbox oil leak, harsh jerking when changing gear.

Camshaft adjusters frequently leak oil. Timing belt should be changed every 100,000 km. A break causes costly valve damage. Combination of a leaking adjuster and an old belt is common.

Symptoms: Oil patch at top of engine, camshaft fault code, rough engine running, check engine light.

The B6294T water pump is driven via an auxiliary drive shared with the power steering pump. The bearing can fail at high mileage, causing coolant loss. Repair time approximately 3 labour hours.

Symptoms: Squealing or grinding from engine block, coolant loss, rising engine temperature

The oil feed strainer to the B6294T turbocharger can block, interrupting oil supply to the turbo shaft. Without sufficient oil, the shaft runs dry and the turbocharger is irreparably damaged in a short time.

Symptoms: Loud screaming or rattling from turbo, power loss, blue smoke, metal particles in oil

Water pump and cooling fan control are prone to failure. The six-cylinder runs hot and tolerates overheating poorly — head gasket damage is a risk.

Symptoms: Coolant temperature rises, fan runs continuously or fails, coolant loss, heater delivers cold air.

The B6294T PCV diaphragm tears with age and allows oil mist to escape into the intake tract. Besides elevated oil consumption, catalytic converter clogging is a risk. Repair: membrane alone takes approx. 15 min; replacing the whole box is preferred.

Symptoms: Hissing noise on cold start warm-up, elevated oil consumption, oil in air filter housing

The 5-cylinder diesel is prone to cylinder head cracks and worn cylinder liners, particularly at higher mileages. Check the coolant level regularly.

The automatic transmission in the S80 I is considered failure-prone and costly to replace. Repair at a specialist costs €3,000–4,000; Volvo dealers charge up to €6,000–8,000. Regular fluid changes delay failure.

The Geartronic automatic gearbox in the S80 I requires a fluid change every 50,000–60,000 km. Volvo declared it maintenance-free — which has led to premature failure in many examples.

On the S80 I, tie rod ends, ball joints and control arm rubber bushings at the front axle wear above average with increasing mileage. MOT inspectors regularly flag these components.

The electric seat adjustment can jam on the S80 I and drive the seat rail to an extreme position. According to user reports, one driver was thrust against the steering wheel and could not move the seat back. Replace the control unit.

The S80 I also suffers from the P2-typical problem of leaking steering racks. The rack loses power steering fluid through aged seals. Reconditioning at a specialist saves significantly compared to a new unit.