Dear Tom and Ray:

I have a question about something that happened to one of the vehicles our company uses. We have a 2005 Ford Explorer that is not used very much in the wintertime. When we tried to start it one cold morning, we thought the battery was weak, because it cranked but didn't start. We had our mechanic come out, but he found that it wasn't the battery. When he tried to start the car, he hit the gas and a chunk of ice shot out of the tailpipe. When he hit the gas again, another chunk flew out. He had no idea how so much condensation could have built up in the tailpipe area. What could have caused this? Thanks! -- Kate

TOM: Sounds like you ordered the Explorer with the optional ice maker. But aren't those usually built into the door?

RAY: I don't think it's condensation, Kate. I can't imagine how you could build up enough condensation to freeze and fully block the tailpipe.

TOM: That's why the car wouldn't start, by the way. When the ice blocked the exhaust from getting out, there was no room for fresh air and gasoline to come in. It was an arctic version of a potato in the tailpipe.

RAY: I think the water came in the same way it went out -- through the tailpipe. How could this have happened? There are two likely scenarios. Scenario 1 is that someone backed into a snow bank.

TOM: Let's say you were parking the Explorer, and you backed into a pile of snow. That wouldn't be enough to stop a running engine, but it would have deposited a serious amount of water in the tailpipe -- which would then freeze, preventing the car from starting.

RAY: Scenario 2 involves neighborhood kids who didn't get an Xbox for Christmas, and needed to find other ways to entertain themselves.

TOM: In either case, I think it's unlikely to happen again, Kate. But in case it does, keep some club soda and a twist of lime nearby.