Tension pulley

What does the tension pulley do?
A drive belt tensioner is a pulley mounted on a spring device or adjustable pivot point that can be used to keep tension on the engine belts. … Both are used to keeptension on the engine serpentine belts to ensure that they can travel the many engine accessories.

How do you adjust a tensioner pulley?
Convert the adjustment bolt privately, top or bottom of the pulley counterclockwise with the ratchet and socket until the accessory belt is loose enough to remove. Tighten the tensioner pulley by turning the adjustment bolt clockwise with the ratchet and socket before belt is tight.
How do I know

A tensioner pulley guides the belt around the tensioner and allows the belt to spin while the tensioner maintains pressure against it. A failing tensioner pulley can cause power loss and harm to your belt-driven systems. You might 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 heating. Pulleys are usually manufactured from either plastic or steel, so verify the pulley itself for just about any damage aswell. At O’Reilly Automobile 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 permits it to keep carefully the serpentine belt taut, in order that the other item pulleys rotate at the same rpm (revolutions per minute) while under the same safe pressure. Tensioner pulleys may also absorb slight shock loads that happen when the air conditioner cuts on and off. As a regularly 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 end of the engine. Put through puddled water “splash-up,” with time the tensioner arm and pulley device can rust. Rust can freeze the automatic tensioner device or rot the shaft bearings, that may 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 mechanism. This can permit the serpentine belt to slip on the tensioner pulley and melt away. Overheated pulley heat results, and eventually the serpentine belt will melt and snap off.
Pulley Tensioner Spring
The pulley tensioner spring inside the housing can become weak from age and repeated contact with heat. This triggers the belt to flutter and skip instead of maintaining a constant pressure on the pulley. Symptoms of a weak spring demonstrate as glazing on the lower of the serpentine belt, with an occasional flickering of the dashboard’s charging light indicator. Squealing or squeaking will always be noticed 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. Bad bearings cause an audible growling noise. The outer ends of the serpentine belt will fray and extend the belt. Gradually the rubberized belt grooves flatten out and cause key slippage. An excessively wobbling pulley can toss the belt off, triggering 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 higher the designated mark, it indicates a stretched belt or a lever arm which has jammed in a single position.
Pulley Misaligment
The tensioner pulley face must match up 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 accessory pulley, can measure the angle. Any off-angle measurement indicates put on shaft bearings in the pulley casing.
Serpentine Belt Noise
A moderately worn serpentine belt gives off a constant squeaking sound during engine idle. Belts that have worn severely task 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 back and forth during idle or higher speeds means the the inside 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 noises.