Dear Car Talk:
I drive a 2002 Infiniti I35 with about 132,000 miles on it. Three months ago while replacing the passenger-side air bag, the Infiniti dealer service department told me the valve covers were leaking and the gaskets needed to be replaced, at a cost of $850. I declined at the time. Two months later, the AAA Car Care Center told me the same thing. Its cost was $750. Sometimes I catch a slight scent of burning oil when getting out of the car. I have been checking the oil level about every two weeks for three months without a discernible change in the oil level. When I served in the engineering departments on Navy ships, every piece of machinery with oil in it leaked oil. Is this a necessary repair? Is it dangerous to drive with this problem? And if I sell this car, is this the sort of thing I am required to tell a potential buyer about?
No, no, and no. If you've been checking the oil for three months and the oil level has stayed pretty much the same, then you're not leaking a whole lot of oil. That means the gaskets are not leaking badly -- at least, not yet. And as long as you keep track of the oil level and add oil when and if it becomes necessary, your engine is in no danger.
The reason you smell burning oil is that it takes only a very small amount of burning oil to create a big amount of smell. When you're driving, the wind disperses the smell. But when you stop, the smell hovers around the car long enough for you get a nostril full of it. That's why I usually break wind while walking.
If you had a big leak from the valve covers, you'd notice it on the dipstick, you'd probably see a lot more smoke, and the smell would be driving you nuts.
I notice that the first estimate you got was for $850, and the second was for $750. So my suggestion is to get eight more estimates. By then, the last guy will be offering to pay you $50 to do the repair.
Actually, $750-$850 probably is the right price. It's a complicated repair because the rear bank of cylinders on this car is hard to get to, and lots of other parts have to be removed first. So don't go with the lowest price you get; go with someone you trust to do it right and trust to put all those parts back together correctly.
But you can live with this until you notice that you're losing a meaningful amount of oil. Or until your car is enveloped by smoke every at stoplight.
And if you sell the car, you can tell the buyer the truth: There's some oil leaking from the valve cover gaskets, but it's not registering on the dipstick, so you were told it doesn't need to be fixed yet.
And if you want to be a real mensch, you can take a couple of hundred bucks off the price to contribute to the repair, whenever the buyer decides to do it. Which means the selling price of the car could be -$100, but at least your conscience will be clear, Richard!