2015 Fiesta SE Serpentine Belt Question

[kjs_fiesta]

There is a noise from my serpentine belt and slight fraying that correlates to a pulley misalignment. The car has about 82,000 miles on it so I'm wondering what is causing this misalignment. It seems to have appeared out of nowhere. Online research show that oftentimes it can be caused by a bad or a worn tensioner but the 1.6L DOHC engine doesn't have a tensioner but a self-tensioning belt.

Any ideas what is causing the misalignment? Could it be that the belt is wearing out early and creating a bit of slack that's causing the misalignment? Or is it the actual pulleys themselves? Which would be a nightmare to replace it seems.

 

[Handy Andy]

The pulley? Er, no not exactly - but what the pulley powers could cause this.

If the belt fraying is outside, like on the broad surface of the belt, then one pulley, usually the water pump one, may have a nick or damage to the surface of it from a picked-up rocks or dropped tool onto it while the engine was running.

The Belt itself is an EDPM - it's a "stretchy" kind so it conforms to the changes in length naturally, so the wearing to me seems to be more from dirt debris of damage while the engine ran, causing the pulley, or other drive groove side components - AC or ALT or even the Harmonic Balancer pulley - to have picked this up - can have sand, dirt even small rocks - that can damage the grooves of the belt - you'll have to investigate

The nightmare is not doing anything at all - then you have a bigger problem.

So replace the belt, to take it off, requires a long handled socket tool or breaker bar to move the nut of the drive pulley (Balance one on the bottom) and use a pry bar or wide blade screwdriver to force the belt to derail - by inserting the tool to apply the flat spot to lift the belt to get it off the grooves and driveline - that you can get access to - like on the AC or Alternator pulley or even the water pump (carefully) and rotate the drive pulley by the breaker bar tool by hand - to advance the belt/tool together to force the derailment so you can get the belt off.

Be careful about this action you're doing; it may have cause this in the first place.

 

[kjs_fiesta]

Thank so much for the reply and the advice! I agree leaving it would be unacceptable since it's my partner's daily driver and the last thing I'd want is her stranded on the highway or something. I take it I have at least some time since the belt looks pretty healthy and the fraying is a few strands on the broad surface of the belt. But I ordered a replacement belt to arrive this weekend.

Since I'm planning on replacing the entire belt anyways, I was thinking of cutting the belt off to not cause any damage to the surface of the pulleys. But just to clarify a few questions since I'm new to DIY is:

1. I would inspect the pulleys by just spinning them and checking for play, correct? Is there a preferred way to clean them? Would I spray brake cleaner on them or should I go at each surface with a plastic toothbrush?
2. If the pulley does have some kind of damage to them, is it possible to just replace the pulley? Would I have to replace the entire thing it powers or remove the engine? I assume that would be outside of my scope as there's no way I can lift the engine out.

I'm not sure what caused this misalignment in the first place as I haven't done anything in the engine bay so far. But I did notice the noise start after I picked up the far from the mechanic. That said, since it was a simple transmission oil change and the mechanic is someone who is very competent, I doubt it was them that caused it. Especially since he informed me of the noise being present when he took it for an initial test drive.

 

[Handy Andy]

You're on the right track!

Always take the time to inspect - the pulleys roll - but have enough friction on them to turn against the belt, but if something were to occur or did happen in time - that generates a condition like flat spotting or rough roll - lobbing - making a simple turn more of a vibration, which can ruin sets of bearings that pulley is supported by, making their seals fail sooner.

However, the pulley may turn freely by hand, but when it's under tension? It can drag - and even though you replace the belt, the pulley and what it's connected to - is still in its same condition when you started this. So, to check for wobble may be possible, the condition may only occur while the engine runs above a given RPM - so the offset or wobble would not be as noticeable until the engine is revved and brought up to load - which you then can hear the howl - but trying to run alongside a car to review the condition - might prove to be more difficult...

IF you can see damage on the surface of the pulley, attempting to re-machine it smooth is not the best route...

• you might want to think about getting a "runout" gauge to see just how much wobble or how bent the shaft that pulley turns - is - before you take it on a long trip even after replacing the belt.

​

• Or a mechanics stethoscope to listen to specific portions of the engine - but is limited to areas that are not moving - so listening for groaning of a bearing is kind of out of the question...

​

To replace the pulley - it is better to replace the whole thing - why? The mileage you have on it now, you're not going to get back any real benefit because the whole mess is already aged this length of time - and when a pully gets damaged, it also tends to wobble the shaft it rotates - so were already at two strikes, the third is what you can't see - under all the seals and inside the engine.

Keep us posted on your progress!

 

[scotman]

I would be looking at all the pulleys for runout and also the shafts they are on for looseness.
The likely culprits for bearings letting go are water pump, alternator and A/C compressor.

 

[kjs_fiesta]

Thank you guys! I'll check it out this upcoming weekend as both my partner and I got the 'vid So she isn't going anywhere and I won't be doing much work on the car.

If I find bad bearings on these components, I guess I'll have to replace them. But my question is, how difficult will it be to replace any of these components? I know the water/coolant pump is essentially a timing belt job since its under the timing belt cover. But what about the alternator, A/C and the crankshaft? Will I need to take the engine out of the bay to do the replacements?

 

[LionsTooth]

Thank you guys! I'll check it out this upcoming weekend as both my partner and I got the 'vid So she isn't going anywhere and I won't be doing much work on the car.

If I find bad bearings on these components, I guess I'll have to replace them. But my question is, how difficult will it be to replace any of these components? I know the water/coolant pump is essentially a timing belt job since its under the timing belt cover. But what about the alternator, A/C and the crankshaft? Will I need to take the engine out of the bay to do the replacements?

There are videos on how to replace the timing belt on YouTube. No you don't need to pull the motor. You will need to devise a tool or rent one to keep the cams in proper rotation to the crankshaft. That will be covered in any video.

 

[scotman]

There are inexpensive tools for stretchy serpentine belt type servicing. This one is a "Lisle" brand.
It has a magnet embedded in each surface that goes against the side of the pulley, this allows you to walk the belt off or onto the pulley depending upon which side of the tool you employ.