NISSAN QUEST

The improved Quest will satisfy minivan fans who want maximum space and lots of cup holders.

NISSAN JUKE

It looks a bit funky, but its turbocharged engine makes it fun to drive.

Chrysler 200

It's not a class-leading car, but it's a big improvement over the old Sebring.

ACURA TL

A makeover gives the luxury sedan updated styling and sharp handling.

Q I have a 2002 Chevy S-10 with about 86,000 miles. Six weeks ago the "service engine soon" light came on. My shop determined it was fault code PO410 and replaced the air pump. Two weeks later, the light came on again, and they said it was just a loose gas cap. Two weeks later it came on again and showed PO410; my shop replaced the air pump and solenoid again. Now, five days later the light is on again. Can you help?

A I checked my Alldata automotive database and found service bulletin 04-06-04-015A, dated November 2006, that says water could cause corrosion in the air pump or vent solenoid. It calls for installing a new air pump along with a new inlet hose and solenoid tube assembly, and rerouting the hose assembly between the engine and fender so that it ends up between the battery and coolant recovery tank.

Have your shop check to make sure the correct, updated air pump was installed and the new hose and tube assembly are properly routed. Also, check the pins and terminals on the solenoid connection -- corrosion could cause an intermittent connection triggering the light.

Q I am the first and only owner of a 1986 six-cylinder Pontiac Fiero with 100,000 miles on the odometer. I keep the car in my heated garage, but it has not moved in the past three years. I pulled it out last month and went for a short drive. The "brake" warning light comes on, and I have no brakes. The pedal goes all the way down to the floor. The brake light stays on for about 15 seconds, then goes off, and I have normal functioning brakes. This happens every time I apply the brakes, but the light comes on only when the vehicle is moving. I am 74 years old and I want to be able to enjoy the car during the summer months.

A I suspect a faulty brake master cylinder. Worn or stiff cup seals in the master cylinder may be allowing a bypass leak when you first apply the brakes. Instead of hydraulic pressure expanding the cups and sealing against the cylinder wall, fluid may be bypassing the seals, allowing the pedal to travel to the floor.

Here's a quick test. With the engine running and the vehicle stationary in Park, gently, slowly and smoothly push the brake pedal down. Does it travel to the floor without engaging the brakes? Now, release the pedal, wait 15 seconds, then quickly stab the pedal firmly as if panic-braking. Does the pedal hold firm with the brakes engaged? If so, you've identified the problem with the master cylinder. A new, or rebuilt master cylinder and a complete flush and bleed of the brake system will hopefully get you safely back on the road this summer with your Fiero.

Q My 2004 Buick LeSabre has 116,000 miles on it. The last three times I have been in rush hour, after 10 minutes of stop-and-go congestion when I accelerate back to normal freeway speed the transmission bucks as it goes into first and then second gear. This problem disappears completely after I turn off the car. Unless I am in this situation, the transmission operates perfectly. I am assuming it might be a sensor.

A The "check engine" light would be on if there were a sensor problem. However, the transmission fluid temperature sensor may be commanding "limp mode" operation because of high transmission fluid temperatures. A scan tool can identify any fault codes and can read the transmission fluid operating temperature to determine if there's a problem.

Internal mechanical problems such as worn valve body components or a worn secondary clutch assembly could also create this symptom. With that many miles on the vehicle, I'd add half a can of SeaFoam Trans-Tune with the hope of eliminating the symptoms.

Motoring note

Take a moment to remember the service men and women who, through their service and sacrifice, have given us the freedom and opportunity to enjoy this Memorial Day weekend.