Auxiliary belt squeaking, pulleys 2007 Ford Fusion

ANSWER : Hello – the noises you describe could be coming from the serpentine belt idler pulley, the belt itself, or the tensioner. I would recommend having the serpentine belt, and idler pulley, including the tensioner – replaced by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs. These tend to wear out at the same time.

ANSWER : Hello there. It is possible that the serpentine belt is not installed straight, which tends to create the type of squeaking noise you are talking about. It is also possible that the pulley was not properly lubricated. If either of these are true and causing the squeak, it should be corrected sooner rather than later, as it can lead to premature wear and tear. The best way to correctly diagnose this problem is to have a professional mechanic come to your location and complete a car is making a noise inspection.

ANSWER : Hello. The smaller belt is known as your timing belt, and it works inside the engine to keep mechanical components aligned with each other during the compression cycle. The serpentine belt, which is the big belt, drives the alternator, water pump, AC compressor, and a couple of other components. If the small belt broke it is likely the timing belt. This will cause the car to stall, lights to illuminate, and can even cause serious damage to the engine. Typically replacing a timing belt is a lot more complicated and expensive than replacing a serpentine belt. You may want to receive a second opinion on the car before you go ahead with repairs.

ANSWER : At the next cold start, try this: Take a spray bottle with some water and spray the belt then start it. If you hear the noise, then the problem may not be with the belt or tensioner. If you do hear it, then it’s possible that one of the pulleys (a/c,water pump,etc) may be slightly glazed or out of round. It’s also possible that a bearing, such as in the water pump, alternator, or a/c compressor clutch may be the issue. Sometimes a bearing that is on it’s way to failure can squeal when cold until it warms up. Alternator bearings are a common source. A mechanics stethoscope may be a good tool to locate a squealing sound. Since the noise is primarily on a cold start, the vehicle may need to sit for several hours or even overnight to get the noise to occur and found with the stethoscope.

ANSWER : 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.

ANSWER : This is okay since there are more notches on the belt than the amount on the sprockets. Once you aligned the first time the belt marks will almost never line up perfectly again. The marks are used to put the belt on correctly. They aren’t used as an indicator after the engine is turned again. You should be okay to start the motor as long as timing marks on pulleys line up. If you run into any issues, have a certified technician, like one from YourMechanic, assist you with the replacement of the timing belt.

ANSWER : I can think of a few possible causes to this issue.
1. You are trying to replace the belt with a new one and may have got the wrong size belt. There are two different 3.0 V6 engines that are available for this vehicle so you may have got the belt for the other engine. The solution to this issue would be to swap the belt out at the parts store for the correct belt and try again.

The belt is the correct size but the belt tensioner is unable to hold tension against the belt causing a lack of traction between the belt and the pulleys. This would result in the pulleys not spinning fast enough to cause any of the belt driven assesories to work properly.
The crankshaft pulley bolt or woodruff key has broken causing the crankshaft pulley to be loose on the crankshaft. This can also cause a lack of tension on the belt causing the belt driven assessories not to work.

ANSWER : The problem with most belt dressings is they work by causing a softening of the rubber compound the belt is made of, which although may be convenient to quickly stop a squeaking noise, in the long run is not a good thing. If you sprayed an excessive amount you have most likely damaged the belt and it is very likely filling up the grooves in your pulleys. My advice is to have a mechanic, remove and replace the belt, and make sure all pulleys are clean.