Drive it forever
Q I have a 2001 Saab 9-3 with 81,000 miles. Over the past month, it has had a problem restarting after it has been driven for a while and then turned off. The engine will not turn over and the only noise it makes is a buzzing sound. After the engine has cooled, it starts right up. The battery is only a few months old, so I assume it is the starter, but the dealer and other mechanics say they can't tell.
A They can't tell until they actually get your car into the shop and check it, obviously. It might be the starter or not. Your Saab uses a starter with an attached solenoid. The solenoid does two things. When it is energized by turning the key to "start," heavy-duty electrical contacts switch the battery's full current across the starter motor's armature. At the same time, the solenoid pulls a yoke that slides the starter gear into mesh with the gears on a flywheel.
That buzzing sound is the solenoid. It's getting enough voltage to pull in, but when the starter motor connects, the extra draw on the current drops the voltage below the threshold it needs to stay pulled in. So it drops away from the flywheel, at which point the voltage goes back up enough to pull it in again. Lather, rinse, repeat.
The first things to check for are a fully charged battery and good connections. That includes the ground strap to the block and frame.
Next, check the voltage at the starter while cranking. You should see a minimum of 7.5 volts at the starter connection. If the voltage is less, you need to find out why. Causes include bad wiring or a bad battery. You also can check battery voltage while cranking. If there is a difference of more than 0.5 volts or so between the voltage at the battery's top post and the solenoid, that means a bad connection somewhere along the way. You can check voltage drop along the length of the line under cranking load as well; it shouldn't be more than half a volt. Ditto for voltage drop along the ground cable.
If all this checks out, your starter solenoid is overheating, and requires too much current to turn over the engine. A new starter may help, but the better cure is to insulate the starter from the exhaust pipe.
Q I was trying to start a siphon with a piece of hose to get some gasoline for the lawn mower. Apparently I aspirated some gasoline; I felt so bad I ended up having to spend a night at the hospital. I think you ought to tell your readers not to do what I did.
A It's true, there's far greater danger to siphoning gas than making your shoes smell like a refinery. Chemical pneumonia is not fun, and that's what can happen if you inhale even a minuscule amount of gasoline.
I admit I have often performed the time-honored operation of sucking on the end of a piece of hose to siphon gas without putting myself in the hospital. Fortunately, age, maturity, and having my own garage mean that I no longer have to siphon my dad's car for gas to put in the dirt bike. But every now and then I still have to empty a fuel tank so I can remove it from a vehicle.
Here's a neat trick that will work on most cars. Use a fairly thin piece of hose, because many of today's cars make it difficult to snake a hose into the tank. Keep feeding hose in until you can blow bubbles in the tank, assuring yourself the end of the hose is indeed submerged in gasoline. Plug the filler neck with a rag, and blow compressed air into the tank from your compressor. The slight pressurization will force fuel up your hose, and when it starts running into your catch container, you can stop blowing. It's easy -- at least if you have a compressor.
Q I believe you had a column on replacing the pins in an electrical connector. Where can you find the tools and replacement parts? I have checked with dealers and parts stores and get nothing but blank stares. Internet searches have also turned up nothing. I can usually muddle through with improvised tools and salvage the connector pins, but it takes a lot of time.
A I just went into the local NAPA auto parts store and asked the counterman. He had at least three different tools and kits to choose from.
Mike Allen is a senior editor for Popular Mechanics magazine. Questions should be sent via e-mail to driveit@nytimes.com. 
