what is causing my 08 sentra to shrill so loudly? When I accelerate my rpm gauge incteases as usual but then starts making a loud slren noise. The speedeter drops to zero and the car loses power.

Sounds like who ever changed your hose may have gotten some anti freeze on the serpentine belt. The noise should eventually go away but I would spray some belt dressing on belt that will help eliminate the noise until the anti freeze wears off the belt. And also it losses power because belt is slipping from anti freeze being on it.

Ashley, could this whining noise be from your transmission? You know, the CVT transmission is good for 10 years or 110,000 miles or at least that's what I read on another forum post. Just an idea? Did you bring your car to the dealer to have them give you an estimate or test drive it? Or, bring it to your regular mechanic.

Uhh, it's not the belt. More likely the CVT transmission.

Bob, I agree with you that it might be the CVT transmission. Ashley, we're presuming that you have this transmission, is that true? Nissan has been dogged by these problems and that's why they increased the warranty. Subaru has a different CVT unit in their cars and it appears to be superior to those in the Nissan cars.

Bob, what's your opinion generally on CVT. I like it on my Subaru. A few years ago I test drove a Nissan Versa in 2009 or 2010 with CVT and was not impressed. My 09 Prius has a CVT like transmission, really a "power sharing transmission " proprietary to Toyota. From all accounts I've heard these power sharing units go for 200,000 miles or so. The Subaru Lineartonic CVT as far as I know has been very good and now they've shelved their old 5EAT automatic transmission to all CVT in their 2015 vehicles. Let me know your thoughts. Thanks.

Mark, my current opinion on CVT transmissions is that if I am car shopping and the vehicle has a CVT, I would not buy it under any circumstances. The current CVTs in my opinion have too many issues, Nissans are really troublesome. Also the long term dependability is still a big question mark. More time and development will make the CVT better.

Bob, more time and development? You know that the initial designs for CVT have been around since Leonardo da Vinci, who, by the way, I would say was a pretty smart guy, do you not agree? And, here are some of the various applications that have been used on CVT since. So, how much extra time do you think is required. Yes, there's been some manufacturing problems with Nissan. Nissan cars generally have been the most inconsistent Japanese brands on the market and I could not recommend them. See these links below. I think the biggest problem with CVT is user acceptance. Subaru makes their own in house CVT transmission. http://www.odec.ca/projects/2007/viva7s2/cvts2.htm http://www.google.com/patents/US8181442 http://www.odec.ca/projects/2007/viva7s2/cvtvsauto2.htm http://www.odec.ca/projects/2007/viva7s2/proscons2.htm http://adventure.howstuffworks.com/outdoor-activities/snow-sports/snowmobile1.htm

I think the issues may be more related to engineering and parts quality. But still, no CVT for me.

Bob, I appreciate what you're saying. At least for my experience so far with the CVT -like, Toyota Prius Synergy Drive, which is actually a power sharing transmission not a true CVT, but, uses the same concept and the Subaru Lineartronic CVT which is now used in all of their automatic models beginning in 2015, I'm pretty satisfied that this is the future. An engineer told me that these systems have less moving parts and are more sophisticated than ever. You know, people like what they know, and change is difficult for many people. The advantages of CVT are many and especially with fuel consumption. I can share with you that when I climb hills with either the Prius or the Subaru, even pulling the trailer with the Outback, the car does not slow down on hills. The engine finds the "sweet spot" with the ever changing gear ratio and just holds the speed of the car there. The only time I ever slowed down with the Prius was traveling over the Eisenhower pass , some 11,000 feet on highway 70. The continued uphill climb depleted all the energy from the electric motor on the uphill climb for 12 or more miles and when I was close to the summit, the engine had no more chance to recharge the battery system leaving me on just the engine. That little 1.5 liter motor had to work pretty hard to get us over the pass, but, it did it. I don't think I'm going to do that again though. I've heard many people who have Prius cars with the same transmission for well over 200,000 miles and while I've heard of people with some Subaru transmissions going well over 115,000 miles, the car's system is still pretty new, introduced on the Outback in 2010. We'll see. For now, I really like the way it drives and it's efficiency. Nissan is not a well regarded car company. And, that's too bad, they've had good cars over the years, but, lately, it's been a hit and miss. Toyota, Honda and Subaru have a much better reputation. I agree with you 1,000 percent that Asian cars are so much better than German cars including Mercedes, BMW and VW. English cars have had a notorious reputation dating back to the 1950s and 60s. If you own an English car like an MG or whatever, you either need to be your own mechanic or have a fat wallet. Good luck to you and kudos on your certified 2014 car purchase, I read your other post.