What does the tension pulley do?
A travel belt tensioner is a pulley mounted on a spring device or adjustable pivot point that is employed to keep tension on the engine belts. … Both are being used to keeptension on the engine serpentine belts in order that they can travel the various engine accessories.
How do you adjust a tensioner pulley?
Change the adjustment bolt on the side, top or bottom level of the pulley counterclockwise with the ratchet and socket before item belt is loose enough to remove. Tighten the tensioner pulley by turning the adjustment bolt clockwise with the ratchet and socket until the belt is tight.
How do I know
A tensioner pulley manuals the belt around the tensioner and allows the belt to spin as the tensioner maintains pressure against it. A failing tensioner pulley can cause power reduction and damage to your belt-driven devices. You may have a failing tensioner pulley if you hear any squeaking or squealing beneath the hood. Bearings on the pulley can wear out, causing noise and warmth. Pulleys are usually manufactured from either plastic or metal, so examine the pulley itself for any damage aswell. At O’Reilly Automotive Parts, we have tensioner pulleys designed for many vehicle models.
The automatic pulley tensioner has an internal spring-loaded mechanism that keeps the serpentine belt under continuous tension. Its design allows it to keep carefully the serpentine belt taut, so that the other item pulleys rotate at the same rpm (revolutions each and every minute) while under the same secure pressure. Tensioner pulleys can also absorb moderate shock loads that happen when the air conditioning unit cuts on and off. As a regularly rotating component, the pulley tensioner can give off some indicators before failure.
Rust and Corrosion
The pulley tensioner sits subjected to the elements at the front of the engine. Subjected to puddled water “splash-up,” as time passes the tensioner arm and pulley device can rust. Corrosion can freeze the automated tensioner device or corrode the shaft bearings, which will cause a frozen placement in the adjustment pressure. Without the proper stress, the belt can slip.
Debris Contamination
Rocks, gravel and other road debris could be thrown up into the tensioner pulley grooves and jam the mechanism. This can allow the serpentine belt to slip on the tensioner pulley and burn off. Overheated pulley temperature results, and finally the serpentine belt will melt and snap off.
Pulley Tensioner Spring
The pulley tensioner spring inside the housing may become weak from age and repeated contact with heat. This causes the belt to flutter and skip instead of maintaining a constant pressure on the pulley. Symptoms of a weak spring show as glazing on the underside of the serpentine belt, with an intermittent flickering of the dashboard’s charging light indicator. Squealing or squeaking will become heard at the belt location.
Pulley Wobble
If the tensioner pulley wobbles on its shaft, this means the inside shaft bearings have worn. This may cause a pulley misalignment. Negative bearings trigger an audible growling sound. The external ends of the serpentine belt will fray and stretch the belt. Sooner or later the rubber belt grooves flatten out and cause major slippage. An excessively wobbling pulley can throw the belt off, leading to all the extras to quit functioning.
Lever Arm Freeplay
Some tensioner pulleys possess markings on the casing that indicate the utmost selection that the pulley can travel. If the lever arm of the tensioner rides under or over the designated mark, it indicates a stretched belt or a lever arm that has jammed in a single position.
Pulley Misaligment
The tensioner pulley face must match to the other accessory pulleys with a parallel alignment. Placing an extended, straightedge ruler against the face of the tensioner pulley, and then flushing it against another 
item pulley, can measure the angle. Any off-position measurement indicates donned shaft bearings in the pulley housing.
Serpentine Belt Noise
A moderately worn serpentine belt produces a constant squeaking sound during engine idle. Belts which may have worn severely task a loud chirping or squealing audio. The cause items to a glazed, worn or cracked belt. Dry or partially frozen tensioner pulley bearings can cause such sounds by wearing out the belt prematurely.
Lever Arm Oscillation
A lever arm that repeatedly oscillates back and forth during idle or higher speeds means the the within damper mechanism in the tensioner pulley has weakened or broken. This triggers sporadic tension pressure on the belt and can manifest itself with intermittent chirping noises.