What does the tension pulley do?
A drive belt tensioner is a pulley mounted on a spring device or adjustable pivot point that is used to keep tension on the engine belts. … Both are used to keeptension on the engine serpentine belts to ensure that they can drive the many engine accessories.
How do you adapt a tensioner pulley?
Transform the adjustment bolt privately, top or bottom level of the pulley counterclockwise with the ratchet and socket before equipment belt is loose enough to eliminate. Tighten the tensioner pulley by turning the adjustment bolt clockwise with the ratchet and socket until the belt is tight.
How do you know
A tensioner pulley courses the belt around the tensioner and allows the belt to spin while the tensioner maintains pressure against it. A failing tensioner pulley could cause power damage and harm to your belt-driven systems. You could have a failing tensioner pulley if you hear any squeaking or squealing under the hood. Bearings on the pulley can wear out, causing noise and high temperature. Pulleys are usually made of either plastic or metal, so verify the pulley itself for any damage as well. At O’Reilly Automotive Parts, we’ve tensioner pulleys designed for many vehicle models.
The programmed pulley tensioner has an internal spring-loaded mechanism that keeps the serpentine belt under continuous tension. Its design enables it to keep the serpentine belt taut, to ensure that the other accessory pulleys rotate at the same rpm (revolutions each and every minute) while beneath the same safe pressure. Tensioner pulleys may also absorb gentle shock loads that happen when the air conditioner cuts on and off. As a constantly rotating part, the pulley tensioner can give off some warning signs before failure.
Rust and Corrosion
The pulley tensioner sits subjected to the elements at the front of the engine. Put through puddled water “splash-up,” with time the tensioner arm and pulley mechanism can rust. Rust can freeze the automated tensioner device or rot the shaft bearings, which will cause a frozen posture in the adjustment pressure. Without the proper pressure, the belt can slip.
Debris Contamination
Rocks, gravel and other street debris could be thrown up in to the tensioner pulley grooves and jam the device. This can allow the serpentine belt to slip on the tensioner pulley and burn off. Overheated pulley temperature results, and eventually the serpentine belt will melt and snap off.
Pulley Tensioner Spring
The pulley tensioner spring inside housing may become weak from age and repeated contact with heat. This triggers the belt to flutter and skip instead of maintaining a constant strain on the pulley. Symptoms of a weak spring show as glazing on the underside of the serpentine belt, with an occasional flickering of the dashboard’s charging mild indicator. Squealing or squeaking will be been told at the belt area.
Pulley Wobble
If the tensioner pulley wobbles on its shaft, it means the interior shaft bearings have worn. This may cause a pulley misalignment. Poor bearings cause an audible growling sound. The external ends of the serpentine belt will fray and stretch the belt. Ultimately the rubber belt grooves flatten out and trigger main slippage. An excessively wobbling pulley can toss the belt off, triggering all the add-ons to quit functioning.
Lever Arm Freeplay
Some tensioner pulleys possess markings on the housing that indicate the utmost range that the pulley can travel. If the lever arm of the tensioner rides under or higher the designated mark, it indicates a stretched belt or a lever arm that has jammed in one position.
Pulley Misaligment
The tensioner pulley face 
must match up to the other accessory pulleys with a parallel alignment. Placing a long, straightedge ruler against the facial skin of the tensioner pulley, and then flushing it against another equipment pulley, can measure the angle. Any off-position measurement indicates worn shaft bearings in the pulley housing.
Serpentine Belt Noise
A moderately put on serpentine belt produces a constant squeaking noises during engine idle. Belts that contain worn severely project a loud chirping or squealing sound. The cause items to a glazed, donned or cracked belt. Dry or partially frozen tensioner pulley bearings could cause such noises by deteriorating the belt prematurely.
Lever Arm Oscillation
A lever arm that repeatedly oscillates backwards and forwards during idle or higher speeds means the the within damper mechanism in the tensioner pulley has weakened or broken. This triggers sporadic tension strain on the belt and can manifest itself with intermittent chirping noises.