IsItAGoodCar
Reliability Guide

Common Problems with the
2004 Lexus RX (XU30)

We've identified 1 known issue that can affect the 2004 Lexus RX (XU30). None are considered critical, but they're worth knowing about before you buy.

1
Known Issues
0
Serious
1
Moderate
0
Minor

All Known Issues

Radiator End-Tank Seam Splitting and Coolant Loss

ModerateCooling System

The original Denso radiators fitted to the XU30 series suffer from age-related embrittlement of the plastic side/bottom end tanks and crimped aluminium core seams. In the UK climate, repeated thermal cycling and road salt spray accelerate corrosion along the bottom core channel, leading to slow weeping of Toyota Super Long Life pink coolant. If left unnoticed, the gradual loss of coolant can cause severe engine overheating and cylinder head gasket failure on the 3.0, 3.3, and 3.5-litre V6 engines.

Est. Repair Cost: £350–£700
Warning Signs:

Sweet coolant smell noticeable from the front grille after driving, Gradual drop in engine coolant expansion tank level over several hundred miles, Pink crusted residue or wet staining along the lower radiator tank crimp, Engine temperature gauge creeping above midpoint under motorway load

What to Inspect:
  • Shine a torch through the lower front bumper aperture to inspect the bottom radiator tank for pink crusting
  • Check the coolant expansion tank cold level and verify fluid is clean translucent pink
  • Inspect the under-engine splash shield for dried pink coolant staining or active drips
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 2004 Lexus RX (XU30)

  • On RX 400h hybrids, verify whether the hybrid inverter intelligent power module (IPM) recall was completed by checking dealer records or running the VIN through Lexus UK.
  • Inspect the bottom corners of the engine radiator for pink crystalline crusting; the factory Denso radiators frequently develop hairline splits along the plastic tank seams.
  • For SE-L models fitted with height-adjustable air suspension, leave the vehicle parked overnight and verify that none of the four corners drop onto their bump stops.
  • Check rear brake discs through the alloy spokes for heavy rust ridges and uneven pad contact; regenerative braking means mechanical brakes are easily neglected in wet UK winters.
  • On RX 300 and RX 400h models, ensure the timing belt and water pump have been replaced within the last 7 years or 100,000 miles, as the MZ-series V6 is an interference engine.
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Check a 2004 Lexus RX (XU30) by Registration