CARspec had the opportunity to address a common problem on the 2006-2008 Lexus RX400h, namely a vehicle that overheats in traffic, intermittent A/C and a coolant leak.
The most common cause is a radiator plugged with road debris like dust, pollen, dirt and other grime pulled through by the fans. Often this coincides with a coolant leak from the passenger side end tank. Here’s what the radiator looks like, the crack on the left of the image:
RX400h Radiator Plugged
The crack forms near the coolant inlet:
RX400h Radiator End Tank Crack
The coolant leaks from the crack quickly. While we can’t say conclusively that the plugged up radiator fins cause the end tank to leak, we speculate that the initial overheating from the plugged up radiator does factor into the radiator eventually leaking coolant. Overwhelmingly the cracked radiators are severely plugged up.
The solution is to replace the radiator with a new unit. In very rare cases a severe overheat can lead to head gasket failure, so CARspec performs a chemical head gasket quick check on vehicles that the owner says has had a boilover or shutoff overheating.
As Minneapolis’s premier independent Toyota, Lexus and Scion specialist we see this failure a few times a year and have the parts readily available to repair the condition, usually next day. If you’ve got an overheating RX400h, don’t hesistate to call us for an appointment at (952)426-4798 today!
