Thursday, December 2, 2010 03:08
We recently received one of those “My Car Is Doing This Bad Thing” notes. (A guy’s 2002 Camry was smoking heavily after cold startup. The smoke stopped shortly afterward. The car, he said, wasn’t using oil.) I was immediately able to diagnose his problem. The diagnosis: Worn-out valve guides.
The valve guide’s purpose it to prevent oil from leaking past the valve stems and into the combustion chamber. They weren’t fully doing their job in our poor questioner’s Camry. When his car is running, the small amount of oil leaking past the guides is mostly burned off with the fuel. But when the car is left overnight, enough leaks into the combustion camber to make the car look like a World War II warship laying down a smoke screen.
How did I know this? The same way a pediatrician knows what’s wrong with your child before you take the little tyke in: The doc has seen 25 cases just like his—most from the same school—in the past day. And that’s the secret your mechanic won’t tell you: He knows what’s wrong with your car because most problems are very common to certain make, models and years.
If you have a four-cylinder Camry that’s somewhere around seven years old or has more than 75,000 miles on the odometer, you probably need new valve guides. And while the mechanic has the cylinder head off, have him replace the water pump. They last about as long as the valve guides. Yeah, if I had wanted to replace valve guides and a water pump at 75,000 miles, I would have bought a Dodge, too.