ISSUE: ‘Engine overheats’ warning message displayed in instrument panel
DIAGNOSIS & SOLUTION: We are having difficulty finding the source of an engine coolant loss on a 2010 Lexus RX 450h. The vehicle also has warning message ‘Engine overheats’ displayed in the instrument panel. All of the coolant hoses seem to be OK and we have carried out a pressure check on the cooling system but no engine coolant leaks were evident. Is this something that has been reported before?
The engine coolant loss your customer is experiencing is most likely due to a known fault with the exhaust gas recirculation (EGR) cooler having an internal engine coolant leak. The fault affects all RX 450h models up to 10/10. Drain the cooling system. Fit a new exhaust gas recirculation (EGR) cooler (fig. 1.1.). The EGR pipe should also be replaced at the same time (fig. 1.2.). Fill the cooling system ensuring the correct ratio anti-freeze content. Carry out road test to confirm the coolant loss has been eradicated.