What does the strain pulley do?
A travel belt tensioner is a pulley mounted on a spring device or adjustable pivot point that is utilized 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?
Transform the adjustment bolt on the side, top or bottom level of the pulley counterclockwise with the ratchet and socket before accessory belt is loose enough to eliminate. 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 courses 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 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 temperature. Pulleys are usually made of either plastic or metallic, so check the pulley itself for just about any damage aswell. At O’Reilly Car Parts, we’ve tensioner pulleys available for many vehicle models.
The computerized pulley tensioner has an internal spring-loaded mechanism that keeps the serpentine belt under constant tension. Its design enables it to keep the serpentine belt taut, to ensure that the other item pulleys rotate at the same rpm (revolutions per minute) while beneath the same secure pressure. Tensioner pulleys can also absorb moderate shock loads that happen when 
the air conditioning unit cuts on / off. As a constantly rotating aspect, the pulley tensioner can give off some indicators before failure.
Rust and Corrosion
The pulley tensioner sits exposed to the elements at the front of the engine. Put through puddled water “splash-up,” as time passes the tensioner arm and pulley system can rust. Rust can freeze the automatic tensioner device or corrode the shaft bearings, which will cause a frozen placement in the adjustment pressure. Without the correct tension, the belt can slip.
Debris Contamination
Rocks, gravel and other street debris can be thrown up in to the tensioner pulley grooves and jam the mechanism. This can allow the serpentine belt to slip on the tensioner pulley and shed. Overheated pulley temp results, and eventually the serpentine belt will melt and snap off.
Pulley Tensioner Spring
The pulley tensioner spring in the housing may become weak from age and repeated exposure to heat. This causes the belt to flutter and skip instead of maintaining a constant pressure on the pulley. Symptoms of a weak spring display 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 listened to at the belt area.
Pulley Wobble
If the tensioner pulley wobbles on its shaft, this means the inside shaft bearings have worn. This will cause a pulley misalignment. Terrible bearings cause an audible growling noises. The outer ends of the serpentine belt will fray and extend the belt. Ultimately the rubber belt grooves flatten out and cause main slippage. An excessively wobbling pulley can throw the belt off, triggering all the components 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 which has jammed in a single 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 equipment pulley, can gauge the angle. Any off-position measurement indicates donned shaft bearings in the pulley housing.
Serpentine Belt Noise
A moderately donned serpentine belt produces a constant squeaking sound during engine idle. Belts which have worn severely task a loud chirping or squealing audio. The cause factors to a glazed, worn or cracked belt. Dry or partially frozen tensioner pulley bearings could 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 inside damper mechanism in the tensioner pulley has weakened or broken. This causes sporadic tension strain on the belt and will manifest itself with intermittent chirping sounds.