How Much To Repair Serpentine Belt

Serpentine belt, tensioner: problems, signs of vesture, when to replace, noises

Updated: November 17, 2022

Serpentine belt.

If you open the hood in a mod motorcar with a gasoline or diesel engine, you will see at least one serpentine belt. See this photograph. At that place are cars with two or iii belts; electric cars have no belts. The job of a serpentine chugalug is to drive accessories installed on your engine such as an alternator, water pump and air conditioner compressor.

A serpentine chugalug is unlike from a timing chugalug. A timing chugalug runs the engine camshaft(s) and is subconscious under protective covers. A serpentine belt is located on the side of the engine and tin exist inspected from nether the hood. What happens if a serpentine belt breaks? What can cause a chugalug to squeal? When should you supplant a serpentine belt? How expensive is information technology?

What happens if a serpentine belt breaks?

Broken serpentine belt.

If a serpentine belt breaks, a car won't be drivable and will have to be towed. If the engine runs without a serpentine belt, it might overheat every bit the water pump will no longer work. A broken chugalug can also damage other parts. We have seen broken radiator shrouds and ripped coolant hoses that were damaged past a ripped belt.

Symptoms of a broken serpentine belt include loud slapping, squealing or knocking noises coming from under the hood. The battery-shaped charging organization warning light might also come on because the alternator will stop charging the bombardment. If a car has a hydraulic ability steering pump, the steering volition get potent.

Mutual belt and tensioner bug that tin can cause a belt to break or produce noises

Here are several mutual problems:

Glazed serpentine belt vs. a new belt Glazed serpentine chugalug vs. a new belt.

1. Regular wear and tear. A new serpentine belt has a soft felt-like surface on the ribbed side. As the belt wears out, the chugalug prophylactic hardens and cracks; coil downward to see the photo of a cracked chugalug. A worn-out chugalug stretches and loses tension. This causes the chugalug to start slipping from time to time. You might hear information technology when the engine is started in the morning or in wet atmospheric condition as squealing or chirping noises coming from under the hood. The chugalug may also appear glazed every bit in this photo.

If there are no other problems and the chugalug tensioner is in good shape, a new serpentine chugalug should set up this problem. Replacing a serpentine belt costs from $18-$75 part plus $50-$150 labor.

Oil-soaked serpentine belt Oil leaks tin impairment a serpentine belt in a brusk menstruation of time.

2. Oil leaks. Sometimes, an engine develops oil leaks effectually the belt surface area, which causes the belt to get soaked in oil, see the photo. Oil or coolant can impairment the serpentine or timing belt fast.

We have seen a new serpentine belt that lasted less than a calendar week in an engine that leaks oil effectually the belt expanse. In this case, there is no indicate installing a new belt. Oil leaks have to be fixed first.
Price to repair oil leaks will depend on the source of the leak. Replacing a valve cover gasket is non expensive ($120-$300), only if the leak is coming from a camshaft seal or other sources, the repair will be more complicated.

An automatic spring-loaded belt tensioner tin seize up inside or clothing out on its shaft

three. Bad bound-loaded automatic belt tensioner. Proper tension is vital for any belt. Often an erstwhile spring-loaded automatic chugalug tensioner seizes upward or wears out and becomes weak. Without proper tension a serpentine chugalug will start slipping. This volition cause the belt to habiliment faster.

Nosotros have seen seized belt tensioners causing a loose serpentine chugalug to ringlet off the tensioner. The symptoms of a loose serpentine belt include a loud squealing noise when the engine is started or when the steering is turned all the way to one side. A serpentine belt that keeps slipping off the pulley is some other symptom of a bad tensioner.
The solution is to replace a serpentine chugalug and a belt tensioner. A jump-loaded automatic belt tensioner costs $xx-$50 for the function, plus the labor ($75-$170).

Automatic hydraulic belt tensioner Often you tin can spot a hydraulic belt tensioner like this one is leaking oil.

4. Problems with hydraulic belt tensioner. Many cars have a hydraulic serpentine belt tensioner, where instead of the bound the tension is maintained by a little "daze absorber" (in the photo). It too can fail.
Symptoms include a leak from the tensioner or a rattling noise from the chugalug area when the engine is running. This particular is mutual to neglect in many cars including Toyota Corolla, Matrix, BMW and Mazda cars.

The fix is the same; a bad tensioner must exist replaced. The belt should exist replaced as well, unless it'southward in like-new condition. A hydraulic belt tensioner costs anywhere from $35 to $75. The labor to replace information technology is $75-$170.

Manual belt tension adjustment Mazda Miata transmission drive belt tensioner aligning.

five. Transmission belt tension is out of adjustment. In some cars the belt tension is adjusted manually, come across the photo. Hither is another instance: the belt tension aligning in Toyota Yaris. Over time, the chugalug stretches and if the tension is not adjusted in time, the belt will start slipping. You have probably seen it: an older Japanese or Korean car makes a loud screeching noise when started.

The solution is uncomplicated: if the belt is still in good shape, the tension needs to be re-adjusted. If the chugalug is bad, it needs to exist replaced and properly tightened.

Misaligned alternator The alternator in this photograph is not lined up with the belt and other pulleys. This acquired the belt to squeal and vesture faster.

6. Misaligned belt caster. A serpentine belt runs on several pulleys. If any of the chugalug-driven devices or a tensioner pulley for some reason is not lined up with the belt, the belt will bleat. Often this problem is discovered after a newly replaced belt still squeals or wears out fast. Ane of the symptoms of this trouble is increased wear on one side of the belt.

Sometimes, you can visually see when one of the pulleys is not lined upward. For instance, in this car, in the photo, an alternator and a belt have been replaced while on a trip, a few weeks agone. Now the chugalug squeaks. Upon closer inspection, we found that the alternator was loose and shifted under angle. This acquired the alternator caster to exist misaligned with the belt, so the belt was squealing and wearing out faster. If you lot look closer in the photograph, you tin see rubber shavings in the area between the belt and the alternator.
The fix, in this case, was to replace the belt and worn-out alternator bolts to align the alternator.

A failed bearing in i of the idler pulleys like this one is another mutual source of the noise.

7. Noisy idler caster or tensioner bearing. To road a serpentine belt, many cars use free-spinning pulleys similar the i in the photo. It'southward chosen an idler pulley. It spins on a little bearing. When that bearing goes bad, information technology can produce a whining/whirring or screeching noise. Because several belt-driven devices can brand a similar noise, this one might accept some time to diagnose.

Mechanics use a special stethoscope to look for the source of noise. A bad bearing inside the alternator, A/C compressor or power steering pump produces the aforementioned type of racket. A mechanic might have to remove a belt and check the devices that are run by a belt i by one.

The repair volition depend on what role is bad. If it'south simply an idler, it's not very expensive: $15-$35 for the part plus $60-$170 labor. Replacing an A/C compressor or alternator could cost from $450 to $850.

When a serpentine belt needs to be replaced

Serpentine belt in good shape This serpentine belt is still in good shape, no need to replace it yet.

A serpentine belt can final from 30,000 to over 100,000 miles. Near machine manufacturers don't specify the serpentine belt replacement intervals, but rather recommend inspecting the belt during regular services. For case, this is what Toyota recommends for the serpentine belt in the 2022 Toyota Camry:

Initial inspection at 60,000 miles/72 months. Inspect every xv,000 miles/18 months thereafter.

Cracked serpentine belt This serpentine belt shows cracks, it needs to be replaced

When you accept your car for a regular oil change service, a mechanic volition look for cracks (see the photo), splits, damaged edges, missing chunks, glazing and other signs of article of clothing. In most cases, information technology'due south easy to see when the chugalug is worn out. A worn-out belt must be replaced. A serpentine chugalug must besides be replaced if it is found to be soaked in oil or stretched.

Serpentine chugalug replacement toll

If your car has two belts, we recommend replacing both at the same time, because y'all are saving on labor. It's besides a good idea to replace an old serpentine chugalug before a long road trip. Read more: Machine checklist before a long trip. Replacing a serpentine belt costs $18-$75 role plus $50-$150 labor.

How easy is information technology to replace a serpentine belt DIY?

On the scale from one (like shooting fish in a barrel) to 10 (go out it to pros) the serpentine chugalug replacement can be rated from three to seven depending on the car. To replace a serpentine belt, y'all will demand a belt diagram that shows the routing. For some cars, the routing is shown in the owner's manual. Another fashion is to depict a routing diagram earlier removing the old chugalug.

In many front end-wheel drive cars with a transversely-mounted engine, the infinite between the engine and the frame is limited and changing a serpentine can be tricky. In some cars, a special tool is needed to release the belt tensioner. To lodge a serpentine belt you might need a VIN number, every bit the belt could be dissimilar for different years and engines. Information technology'south a good idea to compare a new belt to the old one to brand certain the part is right.

If you need proper repair instructions, nosotros posted several links at the lesser of this article, where you can become a subscription-based admission to a factory service manual. Of course, there is YouTube with thousands of machine enthusiasts posting DIY videos.