QWhy did I need front and rear struts on my 2004 Lexus LS430 with only 22,219 miles on it? According to the shop, if a car sits not being driven for some time, adding weight such as groceries or suitcases causes pressure on the struts and they start leaking. Was I taken advantage of?

AYes, absolutely. First, you should have asked the shop to show you the leaking struts. Secondly, you should have taken the car to a Lexus dealer for a second opinion before approving the repair. With so few miles on this relatively new vehicle, even if there was a problem with one or more struts, you could have requested a "customer goodwill adjustment" on the repair.

Shock absorbers and struts don't fail because of increased weight on them. In fact, the hydraulic component of a shock or strut at rest is under no load at all, other than any gas pressure in the fluid reservoir. The only time a shock or strut "feels" anything is when the suspension is in the act of compression or rebound as the vehicle travels over the road surface. Besides, the weight of groceries, suitcases and the like are well within the load capacity of the vehicle.

And finally, don't blame the shop -- blame yourself! You can only be taken advantage of if you allow it to happen.

QI have a 2003 Toyota 4-runner with 95,000 miles. It is the 4.7L V8 and full-time 4WD. During one of my service visits I had the serpentine belt replaced.

After this work I noticed an infrequent drive-line vibration or shudder. It occurs when the truck has shifted into overdrive, vehicle speed is 35-50 mph and with a bit of load like going up a slight incline.

If I immediately get off the accelerator or add throttle, the vibration goes away. If I drive in fourth gear to above 50 mph and then manually shift into fifth gear, the shudder never occurs. I took it to the Toyota dealer, but no diagnostic code showed.

AFrom your description, it's difficult not to focus on slippage in the torque converter as the converter clutch tries to "lock up" into direct drive. You've described the scenario perfectly, including the fact that the shudder stops if you release the throttle or add throttle, both of which would unlock the converter clutch in that circumstance.

Try this. Hold a steady speed while the shudder is occurring, and without changing the throttle setting press and hold the brake pedal down about one-half inch with your left foot. Does the shudder stop? Then release the brake pedal -- does the shudder return?

If so, these are classic symptoms of a slipping torque converter clutch. Adding a transmission additive like SeaFoam Trans-Tune or Lube-Gard may help, otherwise have a complete transmission fluid flush and refill. If the transmission fluid was changed at the same time the serpentine belt was replaced, double check that the correct fluid -- ATF Type T-IV -- was utilized.

QThe "Low Coolant" light stays on in my 2001 Buick Regal even though the radiator is full. Can I just unplug the sensor without replacing it? Could there be another problem causing the light to stay on?

AThe sensor is located on the right rear of the radiator. If you unplug the sensor and the light goes off, the sensor has either failed or it is contaminated with oil from an internal engine oil or transmission fluid leak.