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How To Tell If Tensioner Is Bad

One of the most common symptom of a bad or failing drive belt tensioner is noise from the belts or tensioner. If the tensioner is loose the belts may squeak or squeal, especially when the engine is first started.

How do you test a bad belt tensioner?

Listen for a fluttering” noise while driving or while the car is idling. This indicates the tensioner is too loose. Other noises such as squealing or whirling from the front of the engine mean the spring inside the tensioner is weakening. In this case, the belt tensioner needs to be replaced.

How do you know when to replace tensioner?

Appearance: Cycle the tensioner (mounted on the engine) through the entire range of motion (from stop to stop) by applying torque to the arm with a wrench. The tensioner arm should move smoothly and freely. Solution: If you notice a binding, sticking or grinding tensioner arm, the tensioner should be replaced.

What happens when tensioner fails?

Usually, the tensioner is replaced along with the timing belt. When a timing belt tensioner fails, it loses tension. As a result, the timing belt becomes loose and the valve timing can be thrown off. This leads to engine performance issues.

Should I replace tensioner with serpentine belt?

Tensioners add pressure from an adjustable pivot point or spring mechanism to keep your serpentine belt taut as it circulates around the engine. There is no recommended timeframe in which to replace your tensioner, especially as the belt itself usually needs replacing before the tensioner does.

Can a bad tensioner cause engine vibration?

If you suspect you’re dealing with a failing tensioner or idler, you’ll want to watch for the following symptoms: Excessive tensioner movement – Worn-out coil springs can also cause drive belt tensioners to loosen their grip on the drive belt, resulting in excessive vibration and rattling.

Why is my belt tensioner shaking?

Causes of Belt Tensioner Wobbling In general, belt tensioners tend to get noisy when they fail. If your belt tensioner is chirping or makes other noises, it is often an indication that the part is old and needs to be replaced. You can even remove the belt, spin each pulley, and listen for rumbling or other noises.

Should I replace idler pulley and tensioner?

If there is any wobble, squeak, or undue friction, the idler pulley should be replaced. The best way to maximize the idler pulley’s lifespan is to maintain proper tension on the serpentine belt and replace belts with new ones whenever required.

What happens if you don’t replace tensioner?

Sometimes, the mechanism will weaken or seize up from repetitive use. Other times, the pulley itself can warp, crack, or throw a bearing. This often results in a noticeable squeaking noise from the front of the engine. When this happens, the belt can slip, which will cause damage or weaken it much faster.

Can timing chain tensioner failure symptoms?

You would notice some signs that tell that the chain tensioner is failing, and you can conduct a further inspection to see if there is a need for a replacement. These symptoms often include a knocking sound, check engine light turning on, and an engine misfiring.

Is there any warning before timing belt breaks?

The timing belt can fail without any prior symptoms, so if you’re within the mileage window, you should go ahead and have it replaced regardless. That being said, sometimes your car will give you a bit of warning that the belt is wearing out.

What does it sound like when a tensioner pulley is bad?

When the tensioner or tensioner pulley fails, the loss of tension can cause the belt and pulleys to make high-pitched rattling or chirping noises. If the pulley bearing completely fails, it can also cause a squealing or even a grinding noise. Symptom 2: Knocking or slapping. This can cause a slapping or knocking noise.

Can a bad belt tensioner cause rough idle?

No, not really. Generally a bad timing belt will cause a no idle condition. As in the engine will not run at all. A bad timing belt tensioner might allow a cam to jump a cog and be out of time, but you only get to jump so many cogs before very bad things happen.

How do you know if you need a new idler pulley?

Visual Clues of a Worn Idler Pulley Such wear decreases tension that can cause significant belt slippage. If the pulley or bearing is noticeably damaged, cracking, breaking, seizing, or otherwise coming apart, it is an indication that it requires prompt replacement.

How much does it cost to replace a belt tensioner?

To get the belt tensioner replaced, you will pay anywhere from $140 to almost $400. The price of parts and labor varies from one car to the next, with most labor costs coming in at about $70 or $80.

How long do automatic belt tensioners last?

Most modern cars that roll off the dealer’s lot as a new vehicle will have a 60,000 to 100,000-mile life expectancy for the serpentine belt, tensioners, and idler pulleys.

Can a bad belt tensioner cause misfire?

The belt may oscillate between too little tension and too much tension. The belt will slip and catch, causing noise and vibration. This can cause a change in crankshaft speed that can be severe enough to cause the engine management system to think that a misfire just occurred.

Can a bad pulley cause your engine to shake?

As a result of a tensioner or tensioner pulley failure, the belt and pulleys may make high-pitched rattling or chirpy noises when they lose tension. In the event of a complete failure of the pulley bearing, it can also cause a grinding noise or a squealing.