Dear Tom and Ray:

My wife's car is a 2001 Highlander with approximately 54,000 miles. About two years ago it began consuming oil and has gotten progressively worse. It has failed the last two emissions tests, the check-engine light comes on regularly and it produces a large plume of blue smoke in the morning. Toyota just sent us a notice of an "oil gelling" problem, of which we have all the symptoms. Took the car in Tuesday, and on Wednesday they said it wasn't an oil-gel problem because the valve cover was clean; it was valve seals and would cost between 1,600 dollars and 2,400 dollars to repair. I have begun my argument with Toyota and would appreciate your input/help. Why would a vehicle with 54k miles need valve seals if it wasn't an endemic manufacturing problem? -- John

RAY: Well, here's the background for everyone else. Toyota agreed to fix or replace a bunch of engines made from 1997 through 2002 that failed because their oil turned to sludge.

TOM: Toyota argued that it happened because owners didn't change their oil frequently enough. But lots of owners insisted they had changed the oil regularly. So, to limit the damage to its reputation, Toyota finally said, "OK, our engines are perfect, but we'll fix them anyway."

RAY: So the question is, Do you have a sludged engine or bad valve-guide seals, which cause the same symptoms? And the answer is, we don't know.

TOM: Claylike clumps of oil in the valve train is the typical evidence of a sludged engine. But is it possible to have sludge start in the oil pan instead? We've never seen it, but I suppose it's possible.

RAY: So what you need, John, is a good old second opinion. Go to our Web site, www.cartalk.com, and click on the Mechanics Files. Enter your zip code and look for a recommended mechanic in your area who sees a lot of Toyotas. And pay him to have a look.

TOM: If he finds evidence of sludge anywhere in the engine, then you have a very good case to go back to the Toyota dealer and insist that they fix your engine.

RAY: If, on the other hand, an independent mechanic confirms that your valve-guide seals are to blame, you'll still want to go back to the dealer, but with a different argument. And that argument would be, "Is a Toyota supposed to burn so much oil that it can no longer pass an emissions test at 54,000 miles?"

TOM: We would hope that they would be so embarrassed by this egregious engine failure that they'd offer to fix this no matter what the cause. And if the dealer won't help you, ask to speak with Toyota's Zone Manager.

RAY: Then, if the Zone Manager tells you to go take a hike, have your newly discovered independent mechanic do the valve-guide work -- assuming you like the guy. He'll do the work for less. And you're under no obligation to show loyalty to your dealer unless he demonstrates some loyalty to you, John.