What does the tension pulley do?
A drive belt tensioner is a pulley mounted on a spring system or adjustable pivot point that is used to keep tension on the engine belts. … Both are used to keeptension on the engine serpentine belts so that they can drive the many engine accessories.
How do you change a tensioner pulley?
Flip the adjustment bolt on the side, top or bottom level of the pulley counterclockwise with the ratchet and socket until the equipment 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 while the tensioner maintains pressure against it. A failing tensioner pulley could cause power damage and damage to your belt-driven systems. You may have a failing tensioner pulley if you hear any squeaking or squealing beneath the hood. Bearings on the pulley can degrade, causing noise and temperature. Pulleys are usually made of either plastic or metal, so check the pulley itself for just about any damage aswell. At O’Reilly Automobile Parts, we have tensioner pulleys available for many vehicle models.
The automatic pulley tensioner has an internal spring-loaded mechanism that keeps the serpentine belt under constant tension. Its design permits 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 beneath the same safe pressure. Tensioner pulleys can also absorb mild shock loads that happen when the air conditioner cuts on and off. As a frequently rotating part, the pulley tensioner can provide off some warning signs 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 mechanism can rust. Rust can freeze the automatic tensioner device or corrode the shaft bearings, that will cause a frozen job in the adjustment pressure. Without the proper pressure, the belt can slide.
Debris Contamination
Rocks, gravel and other street debris could be thrown up into the tensioner pulley grooves and jam the device. This can allow the serpentine belt to slip on the tensioner pulley and burn. Overheated pulley temperature results, and finally the serpentine belt will melt and snap off.
Pulley Tensioner Spring
The pulley tensioner spring within the housing can become weak from age and repeated contact with heat. This causes the belt to flutter and skip rather than maintaining a constant strain on the pulley. Symptoms of a poor spring present as glazing on the underside of the serpentine belt, with an occasional flickering of the dashboard’s charging mild indicator. Squealing or squeaking will end up being been told at the belt area.
Pulley Wobble
If the tensioner pulley wobbles on its shaft, this means the interior shaft bearings have worn. This may cause a pulley misalignment. Negative bearings trigger an audible growling noises. The outer ends of the serpentine belt will fray and stretch out the belt. At some point the rubber belt grooves flatten out and cause main slippage. An excessively wobbling pulley can throw the belt off, causing all the accessories to quit functioning.
Lever Arm Freeplay
Some tensioner pulleys have markings on the casing that indicate the maximum 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 one position.
Pulley Misaligment
The tensioner pulley face must match to the other accessory pulleys with a parallel alignment. Placing a long, straightedge ruler against the facial skin of the tensioner pulley, and flushing it against another item pulley, can gauge the angle. Any off-position measurement indicates put on shaft bearings in the pulley housing.
Serpentine Belt Noise
A moderately put on serpentine belt produces a constant squeaking sound during engine idle. Belts which have worn severely project a loud chirping or squealing appear. The cause details to a glazed, donned or cracked belt. Dry or partially frozen tensioner pulley bearings can cause such noises 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 causes sporadic tension pressure on the belt and will manifest itself with intermittent chirping sounds.