For the past 6 weeks or so, the part throttle acceleration of my car felt a bit flat and not quite right. While I was at my last auto-x event, I had the hood up while the car was idling between runs and I heard a hissing sound coming from the area of the PCV valve (forward passenger side valve cover). It was a sound I had never heard before. While a PCV valve does have some noise associated with it, this was much louder than normal. When I got home, I pulled the valve. Everything seemed fine, but when I applied to vacuum to the valve, it would not hold it. There was a small leak or obstruction letting a small bit of air through. The correct operation of the valve is to close under high vaccum situations such as throttle throttle acceleration. At WOT, there is no vacuum therefore the operation of the valve isn't that important. I attempted to clean the valve, but it would still leak. I called around to all the Nissan and Infiniti dealers and none of them stocked the valve because they said it never failed. I would agree, I've never had a PCV valve fail before, but I guess there's always a first time. I ordered a new valve, got it, and tested it. It held vacuum perfectly. I put the valve in and driveability was back to normal. My MPGs are up about 10% too over the past 2 weeks even with the cooler temps.

 

part #?

 

i also hear a hissing noise fromt the pcv area ill check mine out tomm. hopefully the dealer stocks that item.

 

same prob here all fixed

 

I'm hearing the same thing. How many miles are on your car I'm at 108k. How much and where did you get the valve from?

 

you can go to any parts store but i ordered mine from the deal only took 2 days to get in.

 

how much

 

I picked up one up a while back from the dealer for $16 and autozone had the purolator pcv for $15 as well.

 

according to the FSM, you can check this by removing the PCV valve from the rocker cover (valve cover) while idling. You should hear a hissing sound if its working properly. Also, you should feel a strong vaccuum immediately when you press your finger to cover the valve.

 

tollbooth the issue were having is we are hearing a hissing when the pcv is installed in the valve cover.

 

Yep, that's one way to do it. I used my MityVac and attempted to apply about 19hg of pressure. It leaked a bit even with minimal vacuum. I got the OEM valve from Nissan for $12. Keep in mind, the valve is going to hiss, even under normal operation. Mine was hissing very loudly and clearly wasn't performing the way it should.

 

Just saying that you should check this BEFORE you decide its not working properly. Its supposed to hiss somewhat...if its working. It shouldn't be too loud though.

 

That's interesting, back in the day, we changed the PCV valve with every tune up. And back then, we did that every 20,000 miles. I'll check mine as soon as I get a chance.

 

for 12 bucks it was worth changing

 

i payed 9 at dealer