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idling rough

  1. General
    Just this morning without any warning my engine began to make this terrible gravel or sand like noise. It started in a parking lot when I was about to park. When I left I noticed it immediately after starting the engine but the noise dies down and occasionally goes away completely while...
  2. Engine Tunes/Mods
    Ok not sure if I am in the right forum but here it goes... I have an 03 Trailblazer LT EXT 118,000 miles... it has been idling rough for a few months..the hubby changed the spark plugs and found oil on the threads...getting really bad gas mileage...oil pressure is higher, ranging between 40-60...