Lexus IS 300h XE30

Like all Toyota/Lexus hybrids, the IS 300h has no alternator — the small 12V battery is recharged only by the hybrid system when READY mode is on. Parasitic draw from the smart key system, infotainment and DCM module typically flattens the battery within a week of inactivity. Many owners report needing to jump-start after 4-7 days of parking. Battery life is also short, often 4-5 years. The fix is straightforward: either drive the car at least once a week, fit a CTEK trickle charger to the jump-start point under the bonnet, or replace the battery with a higher-capacity AGM. Early 2013-2015 cars had an undersized battery from the factory and benefit from the upgraded part Lexus introduced later.

The 2AR-FSE shares the low-tension oil control rings used across the wider 2AR family. On cars serviced strictly to Lexus schedule (typically 15,000 km / 12 months) with the right 0W-20, oil consumption is rare and the engine commonly reaches 250,000+ km. Where it goes wrong is with stretched intervals, wrong oil grade, or short-trip-only use — the rings coke up, oil consumption climbs, and once cylinder bores are scored the only real fix is a short block (€4,000-6,000 at a Lexus dealer). Topping up frequently or doing a chemical ring decoke can buy time but does not reverse bore wear. Always check oil level on a pre-purchase inspection and ask for a full Lexus service printout — if intervals were skipped, walk away.

The IS 300h uses two electric water pumps — one for the engine cooling circuit, one for the inverter/hybrid system. Forum reports show the engine pump tends to weep or seize between 100,000 and 160,000 km, triggering a coolant warning. Parts are around €250-350, labour 2-3 hours at an independent. The inverter pump is rarer to fail but more critical: if it stops, the car will refuse to enter READY mode to protect the inverter. Both should be checked for weeping during inspection — small puddles or crusty residue around the pump body is the giveaway.

The NiMH hybrid battery in the IS 300h is one of the most durable hybrid batteries ever made — full failures before 200,000 km are rare. When degradation does occur it usually starts as a single weak module (block 8, module 15 is a known cluster point due to corroded tie buckles). Symptoms: ‘EV mode not available’ message, hybrid warning light, drop in fuel economy, occasional limp mode. Module-level repair at an independent hybrid specialist runs €1,500-2,000; full Lexus dealer pack replacement is €3,000-3,500. Crucially, cars with full Lexus history qualify for the Lexus Hybrid Health Check warranty extension, covering the pack annually up to 10 years/250,000 km — a strong reason to buy with main-dealer history.

The pre-facelift (2013-2016) infotainment with the 7-inch screen and Remote Touch joystick is the weakest part of the cabin. A well-known 2016 errant traffic-data broadcast bricked some units across the Lexus range. Other complaints: black screen after 12V battery replacement, slow boot, intermittent freezing, sat-nav lag. Most issues are resolved by a dealer software reset (often free under goodwill) or a battery disconnect/reset. Hardware failure of the head unit itself is uncommon; replacement is €500-600 used. Facelift cars (2017+) with the larger 10.3" screen and CarPlay (post-2020) are noticeably better.

Toyota/Lexus hybrids use a complex brake actuator unit that blends regenerative and friction braking. The IS 300h shares the basic concept with other Lexus hybrids (CT, GS, ES). Failures are uncommon but do happen, usually on higher-mileage cars (150,000+ km) or where DOT 3 brake fluid hasn't been flushed every 2 years. Symptoms: long brake pedal travel, brake/ABS/VSC warning lights together, harsh stop-from-low-speed transition. The unit is a single replaceable assembly: €900-1,500 for the part plus around 3 hours labour. Keep the brake fluid fresh — a 2-yearly flush is the cheapest insurance.