Dear Tom and Ray: It was a rainy afternoon ... I had driven a couple of miles when the car stalled. I opened the hood and stared at the engine. What else is there to do? After 15 minutes and a few more tries, the engine started and I limped home. It was really wet a few days ago, and again the car just would not start. I decide to pop the distributor cap and have a look. In the process, the clip at the back of the distributor broke off. Of course, the friendly folks at my VW dealership say the clip is part of the distributor itself, not sold separately. Sigh. So I got another distributor on eBay, and went out to remove my old one. No luck. It's frozen to the block and won't budge. So far, I have tried repeated applications of PB Blaster and Liquid Wrench. I have tried prying it out with a crowbar. I got the engine running and let it run for a while, hoping the heat from the engine might help the goop work. I also tried tapping it with a hammer, and when I couldn't get a decent swing due to tight quarters, I moved up to an air chisel, and tried to rotate the base of the distributor with that. It is still stuck solid. Any suggestions for me? -- Jim

 Dear Tom and Ray: In a recent column, you got the wrong answer to the "hummingbird" problem. Fifty years ago, my boss in an Air Force research laboratory used this problem to trick those who wanted to upgrade their "subprofessional" status to "professional." He used a balloon instead of a hummingbird, but the physics is the same. The air conditioner's operation is irrelevant, but the closed windows are key. In the closed environment, when the brakes are applied, the air rushes to the front, forming a pressure gradient that pushes suspended objects to the rear. Make MIT proud and admit a mistake. -- Ed

 Dear Tom and Ray: We are Americans living in England, and have a 2000 VW Beetle automatic that I named Betty. I hope you can settle a domestic argument for us (preferably by siding with me). The VW is my "baby," and until I started living with Matt, the car was aging, but otherwise the transmission was fine. In the year since Matt started driving her, Betty's transmission has seriously deteriorated. I think it's because Matt changes gears without pressing in the little button on the shifter. My understanding was that if you don't press the little button before moving the shifter (like from R to D, or D to 2), you can strip the gears and ruin the transmission. Matt says it doesn't matter, and he changes gears in the automatic like it's a stick shift. So, is he hurting the transmission by failing to press the little button? -- Elaine

 Dear Tom and Ray: I have enjoyed your column for years and have always admired your bottomless knowledge and advice for car owners, abusers, know-nothings and BYMs (backyard mechanics). I have but one question I need you to resolve, and then I can drive happily ever after. The "Low Tire Pressure" warning light on my dash came on this morning. So I looked at all four tires, and they appeared OK. Just to be safe, I fired up my air compressor (with apologies to my sleeping neighbors) and topped off all four tires. The tire warning light returned! I eventually checked the manual of my Toyota Tundra, and it told me to check the spare, too. I did, and sure enough, it was low. My question to you is: How did it know? How does the computer system know that the air pressure is low in my spare tire? Weight? Sonar? Internet? Seismic vibrations? Make me happy and tell me the answer, boys. -- Kim

 Dear Tom and Ray: Every time I am braking and go over a bump in our 2008 Prius (a frequent occurrence in hilly San Francisco), the anti-lock braking system kicks in. The problem is that when it does so, it feels like the brakes disengage for a second and the car goes faster. Our Toyota dealer tells me this is the way the ABS is supposed to work, and the brakes aren't disengaging -- the computer system is just taking over the braking process. Is this true? It just doesn't feel safe to me. If I had to stop suddenly, I don't feel confident that I'd be able to in this car. Thanks. -- Betsy

 Dear Tom and Ray: I've heard that each gallon of gas burned by a car releases about 20 pounds of CO2 into the atmosphere. I'm not a chemist, but even allowing for some creative reactions and recombinations going on, how does combusting about six and a half pounds of fuel turn into 20 pounds of CO2? I can't quite get the math to add up. What am I missing? -- Mike

 Dear Tom and Ray: I'm 17 years old and trying to buy my first car, without fiscal help from my parents. I have about 4,500 dollars to spend, but I'm trying to keep it under that. A neighbor is selling a 1993 convertible Olds Cutlass Supreme. It's in fantastic cosmetic shape, there's not a dent in it, it has a brand-new top and it looks fantastic. The problem is that it doesn't run. It needs a new timing belt, which I know can lead to other problems. However, the owners have all of the records from when it was bought new in '93, including every oil change. It was garaged for 11 of those years. They're asking about 2,000 dollars, but will take anything above 1,500 dollars. Should I buy it, knowing that nothing else is currently wrong besides the timing belt, and that I have the money to fix things that go wrong? -- Laura

 Dear Tom and Ray: When I was a kid doing my own tune-ups, I understood that the color of the deposits in the very end of the tailpipe was an indicator of how well-tuned the car was. Tan-colored deposits were good; black and sooty deposits were bad. My new car doesn't get the 24 mpg highway that it should, and the tailpipe has a black sooty deposit. I told the dealer the black soot means that the mixture is too rich, and that causes the poor mileage. He disagrees. Am I right, or is the dealer? -- Jerry

 Dear Tom and Ray: I am really bad at keeping up with timely oil changes on my 2005 Ford Windstar. When I do change the oil and filter, I write the date and the odometer mileage on the side of the oil filter. The last time I changed the oil, I had gone 13 months and 10,000 miles since the previous change. To make up for my lack of timeliness, I drain the oil out of the engine, pour a gallon of diesel fuel into the crankcase, start it up and let it idle for five minutes. I then shut it off, drain it again, replace the oil filter and add new oil. I have been doing this for the past 100,000 miles, and the engine still runs great, with no leaks or burning oil. Is flushing the engine like this OK, or am I eventually going to trash it? -- Paul