Mechanic said this discoloration indicates an impending radiator leak and suggested radiator replacement. Can't find anything about it online. Thoughts? '12 RX450h 133k miles TIA

 

I once poured too much coolant into the overflow container and apparently some released via the radiator cap while driving but that white substance was mostly around the cap and upper hose area. Not sure from your pic which area it is. Are you losing coolant? If not, try cleaning the area and see if the staining reappears.

 

The mechanic needs to do a pressure test before concluding that there is a coolant leak. It is a simple pump with pressure gauge and it fits in place of the radiator cap. He will be able to see the leak immediately or he can wait 5 minutes too see the pressure being held.,

Salim

 

Find a mechanic that doesn't look like this:

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