Q. I put in a power steering pump for a customer and it still makes noise. What can I do to get the air out of the system? It's a 1997 Subaru Outback, and the replacement pump is a factory Subaru part.
A. Subaru power steering systems are somewhat unique in that unlike most cars, if you turn the wheels with the engine off they will sometimes suck air into the power steering system, rather than push fluid out. Over time the air should bleed out by itself--although I have seen some technicians fashion an adapter for a vacuum pump, and apply a vacuum to the pump reservoir while slowly turning the steering wheel.
Q. I'm having a dispute with my neighbor. He says that you always check the transmission fluid in your car with the engine running. When I check the transmission with the engine off, the dipstick reads full. If I check the fluid with the engine running, the fluid also reads full. What is the correct method?
A. Most cars that still have automatic transmission dipsticks require the fluid level to be checked with the engine fully warmed up and running. Whenever in doubt about maintenance, consult the owner's manual.
Q. I have noticed that when it is damp with high humidity, and especially during a driving rain storm, the check engine light comes on. The car is a 1996 Honda Accord with a four-cylinder engine. Any thoughts?
A. The first thing you need to do is have someone check for computer trouble codes. Once you have a code, finding the cause of the check engine light should be easier. One possible problem may be the mass-air-flow sensor. The mass-air-flow sensor is one sensor that can be affected by humidity.
Q. I have a Toyota Corolla, and when I lock the car door the car alarm goes off. What could be causing this?
A. The TVIP (Toyota Vehicle Intrusion Protection) system is quite sophisticated. It uses a series of sensors that detect door openings and glass breakage, as well as an electron control unit that inhibits the starter operation. Toyota has a very specific repair strategy that needs to be followed to properly diagnose and repair the system. The problem could be the control unit, sensor or wiring.
Q. I took my 1988 Ford E-150 on a "two-hour tour" over the weekend. I didn't have any problems on the way up, but once in New Hampshire, I had to jump-start the van to get it going. Then, on the return trip, just as I was coming to a stop at the toll booth in Hooksett, the van just died. I tried to restart it, but got nothing--and I mean absolutely nothing, not even a hazard signal. I pulled over to jump-start it again, but the cables became very hot. I called AAA, and had the van towed home. I let the van sit for a couple of days to "cool down" and it then restarted with no problem. Help!
A. The very first place I would look is at the battery cables. If one of the battery cables has a very poor connection, it could be the source of your problem. Be especially suspicious of the negative battery cable where it attaches to the engine block. I have seen many cases where this cable has just about completely severed from its connection.
Q. I have a 2008 Jeep Patriot with a four-cylinder engine and a CVT transmission. I inadvertently left it in 4-wheel drive for about 1,000 miles, about half of which was at 65-70 mph. Do you think there was any damage done to the transmission? It seems to drive normally now, but what made me aware of its being in 4-wheel drive was a faint burning odor from the brakes.
A. The four-wheel drive system with the continuously variable transmission in your Jeep, like many vehicles, uses the brake system to improve traction. When the wheel sensors detect slipping, the anti-lock brake system will activate one of the brakes to restore traction. It is possible that the brakes may have become slightly overheated during this time.
Q. I have a 2000 Mercury Sable, and every time I start the car it makes a grinding noise before it finally starts. This past weekend, I came home and turned the car off for five minutes and tried to start it. It made the grinding noise, and then just completely conked out on me. It wouldn't start at all. It only made a clicking sound, and it's been doing that ever since. What is the problem?
A. Judging from your description, the starter motor gear drive could be worn. When the starter is removed for inspection, a good technician will also check the engine flywheel for possible damage. If the teeth on the flywheel are damaged the transmission will need to be removed to properly repair the problem.
John Paul is the public affairs manager for AAA Southern New England. He can be reached at firstname.lastname@example.org.