Engine vibration when stopped at a light. No warning lights come on.

On those trailblazers, there are a few things that can cause a vibration when stopped in gear at idle. With mileage and time, the engine mounts wear out and collapse and can cause vibration. The water pump shaft can develop play and allow the pulley to wobble, as well as the fan clutch (which is quite pricey on these vehicles) can also cause a vibration if it has play in it. If you would like to bring in your vehicle for a diagnosis and quote, please contact me at pilonej@autonation.com