Don’t bleed the tires, even in the hottest temperatures

Q: I will be driving in Utah, Nevada and the valleys of eastern California, where temperatures above 110 degrees are not uncommon. If I start the day at the recommended max tire pressure listed on the door placard, do I have anything to worry about, or should I bleed the tires, and how much? Also, a pretty good pressure gauge always gives a reading 1 or 2 pounds less than the built-in tire pressure sensors. Which is likely to be more accurate?

—F.S., Oak Park, Ill. A: Never, ever, bleed air from your tires. Although the tire pressure may increase a bit while driving, it will be much too low the next time you start out. Inflate the tires to the pressure stated on the door placard and leave it there. The tire pressure sensors are very accurate. Manual tire gauges, not so much, but close enough. Incidentally, some folks mistakenly think that the maximum pressure figure molded into the tire sidewall is the inflation pressure, it is not!

Q: I’ve got a 2008 Honda Pilot with about 150,000 miles. Intermittently when stopped at a traffic light, I’ll hear a dull “thump” coming from the rear of the car. It’s loud enough to make me look up in my rearview mirror to see if anything hit me. It only seems to happen when the car is stationary, but in gear, with the brake pedal depressed. I have never heard it when the car is moving, and it doesn’t seem to be related to me depressing or removing my foot from the brake pedal. My Honda dealer kept the car for a day, but couldn’t recreate the thumping. Techs checked the car over, including the brakes, and found no issues. Any suggestions?

—T.K., Barrington, Ill. A: Something is moving and hitting something else. Sure, that sounds simple, but so is the solution. We have a hunch that it’s the exhaust system. At idle, the car has low frequency vibrations, especially while in gear. There may be a loose hanger or a break somewhere in the plumbing.