Piston Slap: The Centurion Loses Its (Dex) Cool

Darwin S. writes:

I have a 1999 Buick Century that now needs constant water. It happens pretty slowly. I recently drained all the water and refilled with water and antifreeze. It doesn’t appear to be leaking anywhere. What’s happening? Thanks.

Sajeev answers:

There are three possible reasons for your Buick’s dehydration.

1. An external leak—which isn’t the problem here.

2. The coolant is pouring into your oil via busted gasket. If so, please accept my apologizes for not getting to your query sooner. Now’s the time to get a locally sourced “LKQ” replacement motor.

3. You’re burning coolant along with gasoline. White smoke from the tailpipe is your best indicator.

If your problem is behind door number three, it’s not the end of the world; new head gaskets are usually the solution. Do a compression test and pull your spark plugs to find the offending cylinder.

Depending on your Buick’s motor, the intake manifold gaskets might be the problem; this was the case with earlier versions of the GM 60-degree V6. Put another way: can Government Motors interest you in one of their new, 90-day-inventory Buick LaCrosse sedans? It’s better than the Century in every way, save for the stupid name.

Bonus! A Piston Slap Nugget of Wisdom:

When seeking the answer to life’s unsolvable questions, always consult your spark plugs. They won’t know if you’ll land that great job, or when you’ll get laid (off), but checking your plug’s condition is like a fortune cookie for your motor.

For the tin-foil hat fans in all of us, checking platinum plugs before 100k miles is a good idea. Well, provided your whip doesn’t require an Act of Congress to remove them. In those cases, just change according to the owner’s manual and hope for the best.