Tom

Tom,

Q I own a 2001 Buick Century Custom that I purchased used with 59,000

miles. I didn’t notice any engine noises until after several oil changes. In the
morning, or when cold, the engine knocks. Usually the knock goes away
after the engine is warmed up. Is there an additive to quiet it down when it is
cold? What are some symptoms to watch for that would indicate a more
serious problem?

J.D.—Kirksville,    Ohio

J.D.,

A Oil additives don’t solve mechanical problems, such as worn main, rod,

cam bearings, or oil pumps. Have an oil pressure test performed to verify the
low oil pressure at cold startup. If it’s low, start diagnostic procedures; that is,
remove the valve covers to check for sludge buildup; remove the oil pan and
check for worn main or rod bearings or an oil pump. I think you’ll find worn
internal engine parts. You may be asking, “Why on an engine with only
59,000 miles?” Three possible explanations come to mind: (1) The oil was
never changed during the life of the vehicle before you owned it. (2) The
engine was badly overheated and burned the oil and thus the bearings. (3)
The odometer was rolled back before you bought it, and the engine has many
more mileage than what reads on the clock.

Did you have a Carfax report done to check the vehicle’s title history
before buying it? If not, don’t make that mistake again.