My engine belt is coming off slowly now it is halfway out. Does this mean i need to replace the belt or it is a faulty engine?

My Ford Fiesta 2002 Facelift 1.6l engine belt slight came off on one of the components that it run on the engine. I am not sure if it is the water pump, alternator or petrol pump. I am not sure whether i have to replace the belt or is it faulty engine that need attention from specialist. I tried to push it back but once i start the car the belt runs back to where it was(wrong position). Everything else is fine. Temperature is normal and water level and oil level is also fine i check it almost everyday before i drive. Please help me. I am scared that it might come off completely and damage the
Experienced mechanics share their insights in answering this question :
When the drive belt is walking itself off the drive pulleys, it can be due to tension or pulley damage. If the belt tensioner spring is weak or broken, the belt will be loose and can begin to come off the pulleys. Also, if any of the pulleys, whether crankshaft, water pump, etc, are damaged and not spinning properly, this can put a side load on the belt and begin pushing it off any or all pulleys. Have a technician inspect the vehicle as soon as possible to avoid over heating the engine.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

A loose or worn belt will cause ticking or rattling noises, poor engine performance and overheating, usually triggering the check engine light. If the timing belt breaks, the engine can`t run — and on some engines that break can cause internal damage.
The serpentine belt need constant tension on the belt to keep it from coming off. If the belt alignment is not aligned then the belt may come off. The tensioner may be out of alignment and not putting enough tension on the belt. Have a mechanic check the tensioner and replace it if needed.
If the belt breaks while you are on the road, the car will break down immediately – and your engine can experience severe damage. You need to look out for signs and symptoms of a weakening timing belt so that you can take action before it is too late.
Your Car Starts Hard And Occasionally Misfires

If your timing belt is failing or worn out it can slip and cause the cylinders in your car`s engine to open and close out of sync. This can cause an engine misfire, which means you should replace your timing belt immediately.

Typically a damaged belt tensioner will not impact vehicle performance. It would cause the serpentine or drive belt to wear prematurely or to squeak – but not cause the acceleration issue.
Belt Noise

As these belts wear out, they can begin to squeak or squeal. They make noise because there is not enough tension on the belt, or because the pulleys are misaligned or weak. Often, simply changing the belt will make it stop squealing. The noise isn`t usually a danger, though it does sound alarming.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My engine belt is coming off slowly now it is halfway out. Does this mean i need to replace the belt or it is a faulty engine?
ANSWER : When the drive belt is walking itself off the drive pulleys, it can be due to tension or pulley damage. If the belt tensioner spring is weak or broken, the belt will be loose and can begin to come off the pulleys. Also, if any of the pulleys, whether crankshaft, water pump, etc, are damaged and not spinning properly, this can put a side load on the belt and begin pushing it off any or all pulleys. Have a technician inspect the vehicle as soon as possible to avoid over heating the engine.

I have a 96 Ford ranger with cel p0340 I have recently done a timing belt, engine runs great replaced cmp sensor cel still on
ANSWER : Hi There,
This may happen for a couple of reasons. First, check to be sure that the connections to the sensor are clean and not faulty or broken. Secondly, check to be sure you replaced the correct sensor as there are two camshaft position sensors in some applications. If you need further help with this, please reach out to us here at YourMechanic as we are always here to help.

Check Engine light comes on, mechanic replaced o2 sensor but light still comes on.
ANSWER : Hi there:

If the mechanic completed the O2 sensor replacement, reset the codes and the error code was triggered again, it is possible that the catalytic converter is damaged and needs to be replaced. However, it’s also very common for the electrical harnesses that power these sensors to become frayed, damaged or faulty; which can also trigger the check engine light. It’s not advisable to drive a vehicle with a damaged catalytic converter for extended periods of time, as it can cause damage to internal engine components.

I have a 2010 camry. I just recently replaced the engine with a 2014 camry engine. Now I have Four engine lights on. I replaced on
ANSWER : If you swapped the engine from a vehicle that is 4 years newer than the car is then you are going to have electrical and sensor incompatibilities that may not be able to be fixed by just a few sensor replacements. There were many changes in computer and emission related items between 2010 and 2014 engines. I would recommend having a mechanic like one from YourMechanic come to you and compare the two engines to isolate the possible differences and see if the problem can be fixed.

belt is missing, squeeling sound before stopped engine, once stopped saw smoke coming from engine department
ANSWER : Hi there:

In cases like then when you’re not sure what component needs to be replaced, it’s always best to have one of our professional mobile mechanics complete a car is hard to start inspection first. This will allow the mechanic to review your car for damage that is causing the symptoms you’re experiencing and then recommend the right replacement or repairs be completed to resolve your issue.

Belts are cracked and need replacing, okay to leave off a/c belt?
ANSWER : Hello. If the belt driving the A/C compressor only drives the A/C compressor and nothing else, you can remove it with no consequences. The fan shroud is not optional equipment however as it has both a cooling system function and a safety function.

Depending on your climate, you might consider diagnosing the A/C system and repairing it. If you use a service such as YourMechanic, it will often be economical enough to do it, particularly if the fault is limited.

Even if the compressor shaft sealing is leaking (would be likely after 25 years), that is fixable in the field. Feel free to contact YourMechanic if you have additional needs relative to this or the replacement of your power steering, alternator, A/C belts.

Do I need to replace timing belt again of replacing water pump?
ANSWER : The water pump and timing belt should be replaced as a set if the coolant leaked on the belt. The coolant leaking on it will damage the belt.

Check engine light refuses to go off after engine replaced
ANSWER : Hello there, you have a long series of issues going on with your 2013 Hyundai Sonata. If you keep getting a repeating oil light on than there is likely a fault in that system.

Since this fault has lasted after the engine was replaced it could be a oil pressure sensor, wiring harness fault, ECU fault, oil pump, oil strainer clogged, or low oil pressure.

To diagnose this issue properly you need a complete vehicle inspection to start from square one and identify the root cause of all this.