What effects can a vacuum leak cause?

There can be a host of problems caused by a vacuum leak, depending on which side of the venturi it is located on and what system the vacuum operates. Some of these can be:
  • ECM / Check Engine light (codes)
  • No Idle, Rough Idle, High Idle
  • Too Rich / Lean
  • Non-functioning accessories; heater blower & vent malfunction, door lock malfunction (mostly Mercedes Benz), brake pedal too hard/soft, windshield wipers won't function, headlight (doors) won't function, rough ride / car height incorrect (air ride system failure)
  • Overheating (boil-over)
  • Loss of power
  • Transmission shift problems
  • 4 wheel drive malfunction
There can be a host of problems caused by a vacuum leak, depending on which side of the venturi it is located on and what system the vacuum operates. Some of these can be:
  • ECM / Check Engine light (codes)
  • No Idle, Rough Idle, High Idle
  • Too Rich / Lean
  • Non-functioning accessories; heater blower & vent malfunction, door lock malfunction (mostly Mercedes Benz), brake pedal too hard/soft, windshield wipers won't function, headlight (doors) won't function, rough ride / car height incorrect (air ride system failure)
  • Overheating (boil-over)
  • Loss of power
  • Transmission shift problems
  • 4 wheel drive malfunction