THE GOODS : Start Repair While Car Is Covered

Question: The warranty on my 3-year-old Buick Le Sabre is about to expire. The engine has been making some funny knocking noises and I am worried that I will have a major engine failure the day after the warranty gives out. Is there anything I can do that would protect me? C.J.

Answer: If the engine did fall apart one day after the warranty ends, you would certainly have a strong case for seeking to get it fixed at General Motors’ expense, though whether the corporation went along would depend on a lot of factors.

You should take the car to your dealership and get the engine checked out under the current warranty. And keep all the work orders and receipts that could demonstrate that you believe a problem exists.

GM has a computer system that allows a dealer to find a complete history of the warranty work that has been conducted on every car through its vehicle identification number.

In deciding whether to cover a repair after the warranty expires, the company will weigh whether the car was properly maintained and any evidence of whether the condition existed during the warranty.

Determining whether a mechanical flaw existed prior to the expiration of a warranty is a pretty subjective judgment. In addition, just because you claim that your engine makes a noise does not prove that a later engine failure was caused by the same problem.

I strongly recommend that you have an engine oil analysis to determine whether the engine is wearing out prematurely. As an engine ages, it produces minute traces of metal from various parts that wear out.

Every component is constructed of different alloys, containing aluminum, nickel, copper, iron, cobalt and other elements. By subjecting a sample of oil to a spectrographic analysis, a laboratory can determine whether the wear of the metals exceeds expected levels for a certain model of engine at a certain mileage.

You can hunt around your local area for a lab that can do the work. Another source of engine oil analysis is through the United Testing Group, a major engine oil analysis laboratory in Atlanta.

You can reach the firm at (800) 394-3669. United Testing offers to do single sample analysis for $17 and will send you a kit in which to package the oil.

The analysis will give you a breakdown of various wear metals in your oil and an assessment of whether they are within normal margins. It will also check the oil for the presence of antifreeze, which indicates an engine coolant system leak, and for gasoline dilution of the oil. Finally, the analysis will determine whether the oil is operating at its rated viscosity.