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Lane Fowler
Lane ... 6/29/2010
2003 Chevrolet Suburban 1500 LT 8Cyl5.3L - Engine
Vibrating/Rough Idle/Sucking Noise when A/C switched on
2003 Chevrolet Suburban 1500 LT 8 Cyl 5.3L

Approximately 85K miles
No real engine work outside of Oil/Oil Filter & Air Filter Changes over the 85K miles (Original Spark Plugs still in-place & expected to go 100K miles)

A/C runs Cold and cools the car fine. However, when switched on, a vibration and/or slight rough idle is noticed. Also when going from a stop, a noise is heard that seems to come from behind glove box area ( A sucking Noise or sometimes maybe a sound akin to a fan blade scrapping)

A/C works fine, but noise and idle issue is a warning that something is not right...

Maybe I should clean the throttle body with aerosol cleaner???? Is it a Throttle position Sensor Issue? There are reall not any vaccum lines on this engibe where a vacuum leak would be suspected?
1 Answer
  • HouseCallAuto
    HouseCallAuto 2/3/2013
    I think that cleaning the throttle body is a great idea. Use aerosol cleaner approved for cleaning the TB. then disconnect the battery for a few minutes to erase the learned idle it had with the TB being dirty. That may correct the rough idle. The noise you describe sounds like there is debris inside the blower motor squirrel cage. Remove the blower motor (like 10 minutes it takes) and clean it out or replace as needed.
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