Q: Car surges at stop light

Hi There, What you are describing sounds like a dirty or faulty idle air control valve. The idle control valve reads the air intake into the throttle body and relays this information to the computer which then uses this information to make adjustments to the fueling of the motor. When this is not working properly, you may notice an erratic idle problem as you describe.

The clunking sound you are describing sounds like you may have a failing axle joint, also known as a CV joint. A CV (Constant Velocity) joint is a shaft that connects the transmission to the wheels, essentially transferring the power from the drive train directly to the wheels. The CV joint is packed with a special grease and sealed tight with the rubber or plastic boot, that is held in place with two clamps. The most common problem with the CV joints is when the protective boot cracks or gets damaged. Once this happens, the grease comes out and moisture and dirt get in, causing the CV joint to wear faster and eventually fail due to lack of lubrication and corrosion. When the CV joint becomes damaged or worn, you may hear a clicking, clunking or popping sound coming from this area as the weight of the vehicle puts pressure on this area and shifts back and forth and side to side. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.