So I have a 1998 ls400 that had a power steering leak with the vacuum tube system. B/C of this issue it was blowing white smoke on start-up. Then I took it in and had it repaired by lexus and the white smoke stopped. Then about 2 weeks SWIM (Someone Who Isn't Me) maxed out the car on empty freeway going 156MPH. A few days later the white smoke appeared.

Basic Question: Can hard driving cause this leak so quickly after being repaired?

Thanks.

 

Letting someone drive the car with that level of irresponsibility is The power steering isn't the first that comes to mind, check your coolant and oil. A high speed run may have done something else in this heat. As robust as these cars are, it is an aging machine and pushing it can be costly.

 

Could be, like RA40 said, coolant and oil. Better check that very soon. But maybe there was still PS fluid in that vacuum hose which goes to the throtle body and, with that much suction, got pulled into the throtle body and is burning itself out. In my opinion, if you got someone driving your car at over 150, you got more problems then white smoke. It doesn't matter how empty the highway is. Those speeds are meant for the track.

 

anyone who would drive any 20+ year old car as-is at those speeds is a complete FOOL - I would only trust an LS400 at those speeds that has ALL NEW suspension components, from one end to the other, and new, very high line tires such as Michelin Primacy at the correct inflation, new steering linkages (ties rods, bushings), recently new or rebuilt brakes, and I would still wear a helmet.