Q: Mechanic said transmission is losing power and occasionally goes into sleep mode, my question is about how long before it goes out

Transmissions cannot lose power simply because they do not generate or create any power. All a transmission on a car does is transfer power developed by the engine to the wheels. If the transmission is intermittently going into what is referred to as "limp mode", there is a possibility of a fix once the cause is identified. Only after a mechanic provides a precise, intelligible and complete account of EXACTLY what is wrong with the transmission can any estimate of remaining life be made. If the present problem is fixable at a reasonable cost, then the remaining life could be measured in years. My suggestion is should get a complete diagnostic, that identifies the specific fault, and then once you have that, you can make a wise determination as to what to do. If your present mechanic cannot explain to you exactly what is wrong with the transmission, simply look for another mechanic who can explain it. If you want a certified mechanic from YourMechanic to diagnose the problem and let you know of your repair options, please request service and the mechanic will resolve it. If you have any further questions, do not hesitate to re-contact YourMechanic as we are always here to help you get results.