Dear Jim,

I'm having some misfiring trouble in the engine of my 2000 Ford Taurus (3.0L, V6).

A couple of weeks ago I got a tune-up, and they put in new spark plugs and plug wires. That didn't fix it, so I took the car back to the shop and the mechanic told me one of the spark plugs was wet, so he'd have to replace one of the fuel injectors. That didn't fix it either.

I went back again, and the same mechanic said the spark plug was still wet, and that's what's causing the problem, but he's not sure what to do. The misfiring only happens when I first start driving, then goes away eventually.

Any idea what's going on?

-- Josh Merriman

Sounds like that mechanic is right, bro -- the misfire is being caused by a wet spark plug.

He replaced the fuel injector, thinking that leaking fuel was making the spark plug wet and ruining the spark it's supposed to give to the engine cylinder.

That didn't work, because leaking fuel isn't the problem. Leaking coolant is.

While your engine is off, water and antifreeze are seeping into the engine block somewhere and getting that spark plug wet. Once you've been driving for a while, the engine gets hot, the leaked coolant burns off, the spark plug dries out and the misfire goes away.

Coolant turning up anywhere on the spark plugs is never a good thing. It means your Taurus' engine block either has a blown head gasket or a cracked head, and those can be very expensive repairs.

These are problems caused by extreme overheating, especially in your particular vehicle model.

Your best bet is to first try a product called K&W permanent metallic block sealer. One 16-ounce can costs less than $10, brother, and you can even apply it yourself.

Follow the directions very carefully, and this stuff potentially could save you buckets of cash on major engine work.

Tip of the Week:

Next time you need an oil change, drivers, consider doing an engine oil flush at the same time. K&W also sells this product in a one-quart can. Just add it to your oil, run the engine for five minutes or so, and then change out the old oil along with the oil filter. The stuff isn't too expensive, and it'll really work wonders on a very dirty engine.

Buffalo Jim, owner of Allstate Auto & Marine Repair in Las Vegas, writes a weekly column. Send your automotive questions to him at buffalojim@lasvegasniftynickel.com. If Jim picks your question to answer in Nuts & Bolts, you'll also be the proud recipient of a deck of official Buffalo Jim playing cards, presented in a classy, tin box bearing his hairy image.