Q: I own a 2008 Kia Optima with 38,000 miles. I frequently have trouble turning the ignition key. I have to vigorously jerk the steering wheel up and down, side to side until finally the key will turn. This may take from one to 10 minutes. This problem may occur several times in one week then not recur for several weeks. I've take the car to the dealer four times. They make an effort to solve the problem but it always recurs. Do you have any ideas?

A: I searched the Internet and found that this is has been an issue for other Kia owners. Potential solutions range from lubricating the lock cylinder, which may be what the dealer has done, to holding the steering wheel in an "unloaded" position while turning the key, to using a mallet to hit the key while it is in the ignition.

First, try a different key. If you don't have a spare, have the dealer cut a new key based on the VIN number of the vehicle. Secondly, try turning the key with the steering wheel "unloaded," meaning it will move slightly in either direction and is not "leaning" against the interlock mechanism. Third, try lubricating the lock cylinder. Many techs suggest using only a dry lubricant like powdered graphite, but if one of the locking pins in the cylinder is sticking to dirt and debris, a light spray lube like Deep Creep might help.

If these steps don't work you could try the mallet trick, but if you do, start with very light taps on the key. And if all else fails, a new lock cylinder might be the answer.

Q: I drive a 2011 Toyota Camry that runs very fine. The only issue I have is a cold start noise. It lasts barely a second or so but it really bothers me. What suggestions do you for me?

A: You didn't describe the noise but the most common cold start noise is a light clatter from the valvetrain, which is not unusual nor harmful. If the noise is a deeper knocking sound it could indicate a main or rod bearing issue. In this case, until oil pressure rises there may be contact between bearing and journal.

But the most likely cause is a problem with the VVT (variable valve timing) gear. Toyota issued service bulletin T-SB-0041-13 in March 2013 that addresses this issue. Apparently the bolts that secure this gear to the camshaft can work loose, potentially stopping the engine. The repair requires replacing the VVT gear, which involves significant disassembly of the front of the engine. Toyota's new car powertrain warranty covers this repair for five years/60,000 miles.

Q: I have a 1991 Ford F-150 4x4 with automatic transmission. The "Rear anti-lock" warning light comes on for long periods, but also can be intermittent. I have replaced the ABS sensor located on top of the rear differential, with no success. I have been told that in this generation of ABS the sensor really has no function in how the brakes actually work and not to be concerned about the light coming on. What's your opinion?

A: The RABS (rear anti-lock brake system) on your 25-year-old truck was a very early version of ABS designed to prevent rear-wheel lockup under heavy braking, regardless of payload in the bed. With the key on and the ABS warning light still on, it is possible to display the exact fault code by momentarily grounding the RABS diagnostic connector under the dash and counting the number of short flashes (from one to 16) from the warning light. Potential faults range from the wheel speed sensor, which you've replaced, high or low circuit resistance, intermittent brake light switch function or problems with the RABS dump valve.

The RABS absolutely does influence how the brakes function, particularly when the bed is empty, so I would not ignore this light.

Paul Brand is the author of "How to Repair Your Car" and "How to Repair Your Truck and SUV," published by Motorbooks.