Q: Identifying cause of serpentine belt being thrown

asked by on June 15, 2017

I have a 2007 Ford Fusion, 4 cylinder. The serpentine belt basically exploded, and I assumed that it was the result of wear; however, after replacing the belt and driving for approximately 100 miles, the new belt was thrown off. I have performed a spot check on each of the pulleys in the drive system, and all seem to be performing properly with the exception of the idler pulley, which wiggles very slightly with a small amount of pressure. I want to make sure I have identified the true cause of the belt being rejected before I replace any the pulleys. My question is, would the small amount of "play" or wiggle in the idler pulley disrupt the belt movement enough to throw it off of the drive?

My car has 180000 miles.
My car has an automatic transmission.

Hi there. It is always a good idea to replace all pulley’s when you have a catastrophic serpentine belt "issue" as you’ve described. In most cases, the force of the belt breaking will cause a slight warp of one of the pulley’s, which can cause the belt to become loose and break again quickly.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

Seat belt chime still chimes with seat belt on how can you disable chime

Hi there. I don't believe this is something that can be disabled. In fact, I believe attempting to do so would be considered tampering with the safety system of car. It is likely that a seat belt sensor is damaged,...

Truck starts to overheat and blows cool from the heater but fixes itself after hitting a bump.

The overheating may also be caused by other issues such as a bad heater core. This is a small radiator used to warm up the interior of the vehicle making the heater operational. A valve controls the flow of hot...

2004 Ford Escape CD4E trans sometimes it engages into Drive, sometime not 2004 Ford Escape

Hi there - your symptoms are indicative of the direct drive/forward clutch drum failure - a fairly common problem with this transmission (CD4E). For further diagnostic assistance, I recommend a transmission inspection performed by a mobile, professional mechanic, such as...

2003 lincoln navigator motor 5.4 does fit in a 2003 ford expedition 4.6?

The hardware and software of the computer (powertrain control module) and transmission control module (TCM) in the Expedition will only work with your present 4.6 L engine. If you change the stock engine to one that is not a catalog...

I have a 2000 ford ranger bumper

I am not sure if the 1997 bumper will fit the 2000 even with brackets you need. You can go to a parts site and check the different brackets you can choose from. It would depend on the bumper you...

KOEO test code 332

Hello there, A few different things can cause insufficient EGR flow. The most likely are: a stuck closed EGR valve a failed EGR valve solenoid faulty oxygen sensor low fuel pressure exhaust leak These can also...

Exhaust was cut off and I need to repair it. What do I need?

As long as the vehicle has a catalytic converter and muffler, you can put what ever pipe you want on the vehicle as long as the pipe is not near any fuel tanks, electrical wiring, and any brake lines. It...

ABS light on

If you are having issues with your ABS system it can be related to a number of things. It is possible that the cause could be related to a faulty wheel speed sensor. The problem could also be related to...

Car won't start after repairs

Hi there. The issue you are having is a symptom of an intake manifold leak. If the manifold is leaking the vehicle's computer will be unable to compensate for the big change in air flow that the leak creates, resulting...

Related articles

Top 10 Best-Selling Cars of 2016
Ford F-series pickup trucks, Toyota Camry, and Honda Civic are some of the best-selling cars of 2016 and all deliver on reliability and efficiency.
2012 Ford F-150 vs. 2012 Chevrolet Silverado: Which One Should I Buy?
When you’re ready to really get some work done, there’s nothing like a full size pickup truck. These trucks are ready to haul a big load and really get in there and get busy. SUVs are great for moving people,...
The Best Used Cars to Buy For Fuel Economy
Saving money on gas is an important factor to consider when buying a car. The Honda Civic, Toyota Prius, and Ford Fusion all have great fuel economy.