I was shifting on my automatic 5At 2006 and i am not able to shift above 1 or just not shifting at all out of the blue. I only have 140k miles and what could it be??

 

Could he a great many things but start by reading the owners manual for proper directions to check your AT fluid level.

 

I had a leak and i fixed it and the mechanic filled it, i took it back in when i had service code. so basically i had knock sensor and found a hose leaking behind the radiator under it has two hoses. Fixed it and filled it.

 

Had a similar problem with my car and I had to replace the valvebody.

 

Did you get the issue fixed Brian?

 

So, It is acting perfectly fine all of the sudden, I was able to shift good, any pointers would be nice? A failing valvebody will act like this?

 

Personally I'd get the transmission flushed BY NISSAN, tell them what it's been doing so they pay extra attention to the fluid when draining it to look for metal. There's a chance that you actually have 140k miles on that fluid, if so it's VERY broken down by this point, the detergents eventually fail and it starts to create sludge that you need to get out of the tranny asap before it completely destroys the valve body.

I don't understand why people think auto tranny fluid is somehow good for the life of the transmission, so many transmission failures can be directly attributed to simply not changing the fluid, and you should check the fluid level monthly as well.

 

For sure follow this advice ASAP. Got my car about 10k miles ago, previous owner was pretty rough on it (the kind of guy who bought used tires...with nails in them). I was new to cars (came from bikes), and had no idea about how important ATF is. Long story short, I drove a mix of sporty/regular with only some drain/fills to get the fluid red again, get manumatic problems, bring it to the dealer for a diagnosed valve body replacement and learn that my transmission pan is full of aluminum. $4500 later, I learned my lesson to watch your fluids like a hawk with these cars.