<|im_start|>system
You are a helpful AI assistant.<|im_end|>
<|im_start|>user
why do cvt engines fail?<|im_end|>
<|im_start|>assistant
CVT engines are a type of transmission system that use two pulleys and a chain or belt to provide variable gear ratios. Some of the most common causes of CVT engine failure are:

- **Overheating**: CVT engines can overheat due to excessive friction, lack of cooling, or heavy load. Overheating can damage the pulleys, the chain or belt, or the transmission fluid.
- **Transmission fluid issues**: CVT engines require clean and adequate transmission fluid to function properly. Transmission fluid can become contaminated with dirt, debris, or metal shavings, which can affect the performance and durability of the CVT system¹³. Transmission fluid can also leak or run low, which can cause the CVT engine to slip or shudder.
- **Stalling**: Some CVT engines may stall or stop working while driving, leaving the driver stranded or in danger. This can be caused by a faulty sensor, a broken chain or belt, or a defective valve body². Stalling can also be a symptom of overheating or transmission fluid issues.

If you notice any of these symptoms while driving your CVT engine, you should take your vehicle to a qualified mechanic as soon as possible. CVT engine failure can be costly and dangerous if left untreated. You may also want to check if your vehicle is covered by a warranty extension for CVT issues, as some manufacturers have offered this option for certain models.

Source:
- CVT Transmission Problems: All That You Need to Know. https://rxmechanic.com/cvt-transmission-problems/
- Subaru CVT Problems | The Drive. https://www.thedrive.com/car-warranty/35585/subaru-cvt-problems
- 9 Most Common CVT Transmission Problems and Symptoms - Causes and Fixes .... https://motorvehiclehq.com/cvt-transmission-problems/
- Common Symptoms of CVT Failure - dubizzle. https://www.dubizzle.com/blog/cars/cvt-failure-symptoms/<|im_end|>
<|im_start|>user
How often do I have to change my transmission fluid? How can I tell if it is still clean and adequate?<|im_end|>
<|im_start|>assistant
The Automatic Transmission Rebuilders Association suggests every 50,000 kms or every two years. For manual transmissions, you should change the fluid about every 50,000-90,000 kms, however, under intense use, some manufacturers suggest changing it as often as every 25,000 kms.<|im_end|>
<|im_start|>user
Could you provide some more detailed information?<|im_end|>
<|im_start|>assistant
Sure, here are some more details:

CVT engines can fail due to several reasons. One of the common causes is overheating, which can occur when the transmission fluid breaks down and is unable to dissipate heat effectively. Overheating can also occur if the transmission fluid level is low, or if the cooling system fails.

Another common cause of CVT failure is excessive strain. This can happen when the transmission is used for towing, or when the vehicle is driven on steep inclines. Excessive strain can cause the transmission belts to slip or even break, leading to a loss of power and possible transmission failure.

Another factor that can contribute to CVT failure is overuse or underuse. If a CVT is not maintained properly or is used for long periods without rest, it can cause the transmission fluid to break down and the belts to wear out. On the other hand, if a CVT is not used enough, the transmission fluid can become stagnant, which can lead to corrosion and failure.

It's important to note that while CVTs are generally reliable, they do require regular maintenance and care to ensure they function properly. This includes keeping the transmission fluid at the correct level and changing it on schedule, as well as avoiding excessive strain or overheating.

I hope this helps. Let me know if you have any further questions.<|im_end|>