Q. My truck was upside down in a ditch filled with water. The engine was not completely submerged, but it was upside down over an hour until the wrecker flipped it back. It runs and smokes (and is in the shop) but hasnt been run long. Will replacing fluids and oil be optimal, or should I be concerned with more serious long-term damage?
A. Certainly changing all the fluids would be beneficial. My biggest concern is that the engine suffered some internal damage when it was first started. If there was water in the engine and the engine was started, it could have easily bent a valve or connecting rod. I would drain and refill all fluids and perform a compression test to look for damage.
Q. My 2009 Caddy CTS has some moisture inside the headlights. Is this something I should worry about?
A. It is possible the seal for the bulb assembly is allowing some moisture into the headlamp capsule. It is possible for the inside of the headlamp assembly to build up with mold and mildew, dimming the output of the light. I would take the car back to the dealer and have them repair or replace the headlamp while the car is still under warranty.
Q. Im interested in a Ford Flex. Do you have any comments on repair history, safety, or general drivability?
A. The Flex has been rated by both the National Highway Traffic Safety Administration and Insurance Institute of Highway Safety with their top scores. It is my opinion that in recent years Ford products have had a better than average repair/reliability rating. The ride is smooth and handling is actually quite good for a large vehicle. I also like the seating and versatility of the cabin. Add in optional all-wheel-drive and the new EcoBoost engine that delivers six-cylinder fuel economy and eight cylinder performanceI think the Flex is a winner.
Q. I have a 2000 Ford Ranger with 88,000 miles. When I come to a stop, the brakes start to pulsate as if it is activating the anti-lock brake system. It started 4-5 months ago on an occasional basis and now it occurs almost every time I come to a stop. Its not a warped brake rotor issue and it only does it when coming to a stop (under 10 mph). It happens in both forward and reverse, certainly mimicking the activation of the anti-lock brake system as you can feel the brakes rapidly pulsate. Any ideas?
A. The common cause is a faulty vehicle wheel sensor. Over time the sensors can rust and cause the anti-lock brakes to activate. A technician will generally measure the value of the wheel sensors to determine which one is at fault.
Q. Over the past two years, my 2004 Chevy Malibu Maxx has occasionally had trouble starting. It shudders as if it is going to catch and run but it doesnt. This happens off and on, sometimes several times in the same day or it could go for months without incident. My mechanic checked it on the machine and couldnt find anything; he suggested it could be the fuel pump. Any help would be appreciated.
A. The most common cause of this intermittent problem is a faulty ignition switch. A technician may be able to watch the voltage going to the computer when the engine is cranking. If the voltage drops off, look at a possible ignition switch failure.
A version of this article appeared in print on Sunday, February 28 on page J11 of The Boston Sunday Globe.