I don't have any advice, but I do have the same problem with a blown head gasket.
My '97 LX450 has only 76,000 mi. This seems way too early for a head gasket.
Is there Lexus / Toyota technical service bulletin or something that documents this as a common problem? I am only about 10 months out of the factory powertrain warranty.
Does anyone have advice on how to approach this with Lexus?
Very disappointed -
Matt