I have a 98 ES300 with a clean engine, no sludge. I get the momentary puff of smoke at startup. My mechanic (whom I trust, family's been with him for 15 years, specializes in Japanese makes) tells me I need a valve job. I've read on here that the smoke is symptomatic of leaky valve stem seals, and that it poses no mechanical danger. My mechanic disagrees, saying that the smoke is going to coat the exhaust system, and if I let it go too long, it's going to require greater repairs because of this.
Is this true? I don't mind the smoke at startup, and I don't want to put down another 1-2K yet for a repair that's not urgent.
