why do cvt engines fail?
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/
How often do I have to change my transmission fluid? How can I tell if it is still clean and adequate?
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.