Q My wife bought a used 2000 Subaru Legacy. All four tires keep losing pressure -- 15 psi or so from each tire every two weeks. The dealer blames it on the aluminum wheels, saying "aluminum wheels leak." Another shop noticed some small cracks on the tire sidewalls and says the tires may be leaking pressure through the sidewalls. Do you have an opinion here?

A With that rate of leaking from all four tires, I suspect most of the air is escaping where the tire seals to the rim. This is not unusual with alloy wheels, particularly with replacement tires. In northern climates such as ours where salt is used on the roads, corrosion can occur in the contact area between tire and rim. Most tire dealers can deal with this by thoroughly cleaning any corrosion and debris from this surface, then treating the bead area on the rim with a sealant.

Although I'm concerned about any cracking or "checking" in the tire sidewalls (it's time for new tires!) I don't think these are the source of the leak. When you have new tires mounted, make sure the dealer addresses potential air leaks from the tire bead area.

Q Every year when temperatures drop below 25 to 30 degrees, my '02 Dodge Intrepid "whistles" intermittently when I am on the road. What would cause this? Do I need to do anything?

A Do you recognize the tune? Maybe you could sing along. You didn't say whether the whistle is coming from the engine/drivetrain or vehicle's body. Assuming it's from the engine, I'd suspect an air leak in the induction system upstream of the throttle body. Cold temperatures can cause molded plastic parts to distort, which might create a small air leak. Upstream of the air cleaner, this would not be a big concern.

On the other hand, if the air leak is downstream of the air cleaner or in the throttle body, it could create a drivability issue. My suggestion would be to take apart the plastic induction components, check for damage or cracks, and reinstall them carefully.

If the whistle originates from somewhere on the vehicle's body, try to locate the source as closely as you can. Check window and door gaskets and seals, then clean and lubricate them with aerosol silicone.

Q While running errands about two years ago, I noticed that the turn signals, power windows and heater motor were not functioning on my 2002 Dodge Intrepid. Upon restarting the car I discovered that all three were working again.

Later, the same three controls failed during a short trip. But now the functions don't return right away.

Two service advisers told me that the problem can't be diagnosed until the problem exists when I arrive at the dealership. I think that with the symptoms being consistent, a professional could at least guess.

A I'm willing to offer an educated guess. All three circuits are energized through the same connector/circuit from the ignition switch, yet all three are protected by different fuses.

Conclusion? Worn or intermittent contacts in the ignition switch itself or high electrical resistance in circuit A22, which runs through connector 10 in the ignition-switch harness connector in the steering column.