Dear Tom and Ray:

Well, I'm using that old line, "I'm writing for a friend." But in this case, it's actually true! A friend of mine recently bought a brand-new 1998 Dodge Neon. After five months of blissful ownership, the Neon refused to start when it got cold this winter. We live in Minnesota, so I do mean COLD. She had it towed to the dealer, who told her that the engine was flooded and that it wasn't covered by warranty. They charged her $100 to "unflood" the engine and change her oil, because they said gas had gotten into the oil due to the flooding. They said that the reason it flooded was that it was too cold for the gasoline to become an aerosol, so it couldn't ignite. It hasn't been that cold since, but I'm just wondering if the dealer knew what he was talking about. Or did he just take my friend for a ride? -- Marc

Ray: Sounds pretty reasonable to us, Marc.

Tom: When all is right with the world, gasoline comes into the cylinder as a vapor. The fuel injectors spray the gas in under high pressure. And that gasoline "spray" or "vapor" is easy for the spark plug to ignite.

Ray: But when it's butt-freezing cold outside, as soon as that vapor hits the cold, metal cylinder walls it condenses and turns back into a liquid.

Tom: And in liquid form, gasoline is surprisingly hard to ignite. Plus, the liquid gasoline can actually "wet" the electrodes on the spark plugs (that's like wetting the head of a match), and a wet electrode can't make a spark. Under these conditions, the engine is said to be "flooded."

Ray: So if you think you've flooded your car (if it doesn't start in the first 30 seconds of cranking), stop trying to start it immediately. You'll only make it worse by cranking it. You'll just be pouring more gas into the cylinders. That's undoubtedly what your friend did. In fact, she dumped so much gas in there that a lot of it leaked down past the piston rings into the crankcase. And that's what contaminated her oil.

Tom: So once the engine is flooded, here's what you SHOULD do: Try to start it one more time with the gas pedal held all the way to the floor. That sounds counterintuitive, but fully depressing the gas pedal does two things. First, it opens the throttle and lets extra air into the cylinders. Second, it sends a signal to the car's computer that the engine is flooded. The computer then greatly reduces the amount of gasoline sent in by the fuel injectors. So if the engine is not flooded too badly, you may be able to get it started that way.

Ray: On the other hand, by the time you do that, it may already be too late. So if it still doesn't start, then you simply have to wait until the spark plugs dry out. That can take anywhere from an hour to several hours.

Tom: Or perhaps a fortnight, depending on the outside temperature and how badly you've flooded it.

Ray: So in the future, tell your friend if the car doesn't start on the first or second attempt, she should use the "foot-to-the-floor" method. And if that doesn't work, she should give up, go back inside and congratulate herself on earning an unexpected morning off from work.

Wait! Don't buy another car without the mechanic's checklist that's included in Tom and Ray's pamphlet "How to Buy a Great Used Car: Secrets Only Your Mechanic Knows." It will help you get a good used car and avoid the clunkers. To order, send (check or money order) to Ruin, P.O. Box 536475, Orlando, FL 32853-6475. You can also order online.

© 1999 by Tom and Ray Magliozzi and Doug Berman Distributed by King Features Syndicate, Inc.

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