Remove ad logos on vehicles with ease

Dear Mike: How do I remove the plastic advertising-logo badge the dealer pasted on my vehicle without damaging the vehicle’s finish? It’s probably been on less than a year.

— J.S., via e-mail

A: The same problem arises with bumper stickers, parking permits and vinyl-tape stripes that have been on for more than a few months — the vinyl gets brittle in the sun and won’t peel cleanly.

There are a number of products that will get it off. My favorite is 3M Woodgrain and Stripe Remover. While you may not find this on the shelf at every chain store, you can buy it at auto-parts stores, especially those that sell to professional car painters. In fact, you can even order it online these days. Follow the directions on the can, and work in a well-ventilated space.

Or you can use another, more readily available product called Goo Gone that is sold with household cleaners and solvents. However, I caution you that this can be a little too aggressive for cars that have been repainted with lacquer paint, so keep that in mind.

You also may be able to get the job done with stuff commonly found around the home, thanks to a trick I picked up from a guy who did pinstriping. Park the vehicle in the shade, and start by cleaning any dirt or grease off the surface for a few inches in every direction from your unwanted sticker.

Cut a piece of plastic food wrap, or even a piece of a plastic trash bag, a few inches larger than the sticker. Spray the surface of the sticker liberally with household ammonia and cover it with the plastic. Wait 10 minutes, and repeat with fresh ammonia.

The ammonia will soften the adhesive, but not affect the strength of the vinyl. Remove the plastic, and the vinyl sticker should pull off easily. Clean up any remnants of adhesive with a soft cloth and motor oil, penetrating oil or citrus solvent. Rub very gently to avoid leaving scratches in the paint, and don’t try to scrape with a credit card, a kitchen-style abrasive pad or a Magic Eraser Sponge, any of which will leave a big scratched area — and don’t ask how I know this!

One caveat: The paint under the sticker may well have faded less than the rest of the paint. This occurs especially with reds.

Dear Mike: My 1995 Olds Cutlass has 37,000 miles. It’s loaded with everything, including the theft deterrent and the brake-shift-interlock system. Problem is, I can’t get it out of park. I’ve done everything. I’ve depressed the brake pedal really hard, and still it will not come out of park.

— W.S., Charlestown, S.C.

A: Is your car parked on an incline? If so, the weight of the car may be bearing against the parking pawl in the transmission and preventing it from disengaging. Give the lever a bigger yank. If the hill is steep, you may need to get a couple of big guys to push the car uphill an inch or two to unload the pawl to get it out of park.

To prevent this problem when parking on a sloping surface, set the parking brake before you put the car in park. This will keep the pawl from engaging at all.

If the car is parked on the level, however, your problem may be a malfunction of the interlock.

The brake-shift interlock is not an option, nor is it part of the theft-deterrent system. It’s standard equipment on almost every car today. It exists because too many people used to have accidents caused by starting the car and not being able to distinguish between the brake and the accelerator, which would send them rocketing away into the swimming pool or out into traffic.

The interlock prevents this by forcing you to have your foot on the brake before the car can shift into either forward or reverse gears. It’s a simple solenoid that immobilizes the shift linkage unless the brake pedal is depressed.

Check for a blown fuse, a malfunctioning switch — which may or may not be the same switch as that for the brake light — or a malfunctioning or improperly adjusted solenoid. Do your brake lights work? If not, it’s a good bet that this is where your problem lies.

Dear Mike: My 1997 Taurus runs well until it goes about 50 miles on the freeway. Then the transmission disengages until it cools down, after which it’s fine again. My mechanic says that he has no idea why this is happening.

Is there any way I can try to diagnose this?

— O.L., San Diego

A: Ah, every mechanic’s worst nightmare: a car that requires an hour-long test drive before it will show the symptom that the owner swears happens all the time.

I suspect that your transmission problems are heat-related, but, as to the specifics, I really have no clue. Beg, borrow or rent a scan tool. These tools track the operation of your vehicle’s sensors and electronics. While scan tools are often available for rent, some auto-parts stores will actually lend one to you with the understanding that you will buy any necessary repair parts there.

Hook up the scan tool and drive the vehicle until it malfunctions. The scan tool will register which sensor has an abnormal reading and take a snapshot of the engine’s data stream at that moment.

Will this tell you how to fix the problem? Maybe. A scan tool will tell you only that a certain sensor’s data is out of range. It’s up to you to determine if the sensor is bad, if its wiring is damaged or if it’s something else. You can check oil-temperature and oil-pressure sensors, as well as the status of shift solenoids and the torque-converter clutch.

With this information, your mechanic should have an easier time making the diagnosis.