When I turn my key over in my 2003 Chevy Trailblazer LT there is a loud buzzing sound from under my hood on the drivers side and the buzzing even happens while I am driving as well
LOUD BUZZING FROM UNDER THE HOOD
- Thread starter MotorboatDDs
- Start date
A few "Possibles"
(1) A Bad: Power Steering Pump Bearing, Alternator Bearing - Idler Pulley Bearing - Water Pump Bearing, or the Belt Tensioner Bearing ... Easily Diagnosed by the Temporary --REMOVAL -- of the Serpentine Belt... Then briefly Start & Run the Engine. IF the Sound disappears during the First 30 Seconds or so of performing this Test... then it is one of the Components mentioned above... Remember to Re-Install the Serpentine Belt.
Observe @MAY03LT perform this Diagnostic:
(2) There might be a Leak from the Power Steering Hoses at the Rack & Pinion Steering Unit sufficient to have Drained down the PS Reservoir of enough Power Steering Fluid to make the Pump express its 'displeasure'. Unscrew the PS Cap and observe the Dipstick Fluid Level.
(3) Something may have become --wedged-- in between the Electro-Viscous Pump Blades and the Shroud and causing a Vibration or a Flutter. A look-see with a *Graduated Eye-Ball* will find anything like this problem being *Stuck* inside there....and just as easily removed.
(4) One of the Relays in the Under-Hood Fuse Box may have gone --sideways-- and is Vibrating excessively. Touch the Tops of ALL of the Black or Gray Plastic Covered Relays --One at a Time-- to sense for the presence of any Excessive Vibration.
(5) In a "Worst Case Scenario"... It could be coming from a Worn Out Timing Chain Set ...including having a Fully Extended Timing Chain Tensioner...Worn In Timing Chain Guides... and Timing Issues causing PXXXX Codes to set because the Crankshaft Sensor (CKP) when compared to the Absolute Position Proof of the Exhaust Camshaft's Position via the (CPS) Sensor can Neither agree any more as to WHEN to Inject Fuel via the EFIs, Nor WHEN to Fire the COP (Coil Over Plugs) for the Spark-Ignition Timing just Before Top Dead Center (BTDC) arrives. Have someone HELP You by Opening the Oil Filler Cap...and -- LISTEN ING CLOSELY -- for the Buzzing Sound to become LOUDER while You are Raising the RPM. Beware the presence of the Dreaded P1345 Code in such cases.
(1) A Bad: Power Steering Pump Bearing, Alternator Bearing - Idler Pulley Bearing - Water Pump Bearing, or the Belt Tensioner Bearing ... Easily Diagnosed by the Temporary --REMOVAL -- of the Serpentine Belt... Then briefly Start & Run the Engine. IF the Sound disappears during the First 30 Seconds or so of performing this Test... then it is one of the Components mentioned above... Remember to Re-Install the Serpentine Belt.
Observe @MAY03LT perform this Diagnostic:
(2) There might be a Leak from the Power Steering Hoses at the Rack & Pinion Steering Unit sufficient to have Drained down the PS Reservoir of enough Power Steering Fluid to make the Pump express its 'displeasure'. Unscrew the PS Cap and observe the Dipstick Fluid Level.
(3) Something may have become --wedged-- in between the Electro-Viscous Pump Blades and the Shroud and causing a Vibration or a Flutter. A look-see with a *Graduated Eye-Ball* will find anything like this problem being *Stuck* inside there....and just as easily removed.
(4) One of the Relays in the Under-Hood Fuse Box may have gone --sideways-- and is Vibrating excessively. Touch the Tops of ALL of the Black or Gray Plastic Covered Relays --One at a Time-- to sense for the presence of any Excessive Vibration.
(5) In a "Worst Case Scenario"... It could be coming from a Worn Out Timing Chain Set ...including having a Fully Extended Timing Chain Tensioner...Worn In Timing Chain Guides... and Timing Issues causing PXXXX Codes to set because the Crankshaft Sensor (CKP) when compared to the Absolute Position Proof of the Exhaust Camshaft's Position via the (CPS) Sensor can Neither agree any more as to WHEN to Inject Fuel via the EFIs, Nor WHEN to Fire the COP (Coil Over Plugs) for the Spark-Ignition Timing just Before Top Dead Center (BTDC) arrives. Have someone HELP You by Opening the Oil Filler Cap...and -- LISTEN ING CLOSELY -- for the Buzzing Sound to become LOUDER while You are Raising the RPM. Beware the presence of the Dreaded P1345 Code in such cases.
Last edited:
Mooseman
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