# Where is the PCV valve?



## pir8 (Dec 1, 2005)

Hi, Newbie question. Does my 1998 Nisssan Frontier (KA24DE) 4cyl 2.4L engine have a pcv valve and if so, where?

The only think I see is a tube coming from the top of the valve cover going into the air cleaner, but there is no valve on the output of the vavle cover. Its just a cast alum elbo.

Any ideas?


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## jerryp58 (Jan 6, 2005)

pir8 said:


> Hi, Newbie question. Does my 1998 Nisssan Frontier (KA24DE) 4cyl 2.4L engine have a pcv valve and if so, where?
> 
> The only think I see is a tube coming from the top of the valve cover going into the air cleaner, but there is no valve on the output of the vavle cover. Its just a cast alum elbo.
> 
> Any ideas?


You may want to check out this thread.

If you do a *Search *on _PCV _you'll probably find more. I thought there was one out there with a good picture.


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## Oldnissanguy (Jan 6, 2005)

That's the crankcase breather tube. Next time you change the oil, look forward of the oil filter mount with the oil filter removed and you'll see the PCV valve. You have to remove the oil filter to get to it.


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## pir8 (Dec 1, 2005)

Hey, thx guys. I'll check it out there tonight. I called a nissan dealer by my place to ask for it because I was thinking to just order it so I could see what it looks like. But the guy told me it doesnt have one. In any case. I'll go check... 

"It is located below the power steering pump and behind the altenator and is plugged into it's own seperator that attaches to the front timing cover ( it's a black box)"


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## Oldnissanguy (Jan 6, 2005)

Execellent discription of the location. Makes is sound like it's hard to get to doesn't it?


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## jerryp58 (Jan 6, 2005)

pir8 said:


> Hey, thx guys. I'll check it out there tonight. I called a nissan dealer by my place to ask for it because I was thinking to just order it so I could see what it looks like. But the guy told me it doesnt have one. In any case. I'll go check...
> 
> "It is located below the power steering pump and behind the altenator and is plugged into it's own seperator that attaches to the front timing cover ( it's a black box)"


Do you have a PCV filter element inside of your air cleaner? As stated in that thread, that's the only scheduled maintenance item for the PCV system on my '04.


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## Oldnissanguy (Jan 6, 2005)

Time for an explaination. All cars build up pressure in the crankcase (also known as 'blow by'). It gets worse as the rings wear and more gases slip by them. In the days prior to PCV valves, these gases escaped into the atmosphere via a crankcase breather somewhere on the motor. 

When PCV valves were introduced, they were normnally mounted on the valve cover and routed directly into the air cleaner housing. The old style breather was retained to offset the negative crankcase pressure caused by PCV valve suction. However, as the motor wore and the the carnkcase pressure exceeded the suction of the PCV valve, you still had gases going into the atmosphere.

The typical current NISSAN system replaces the carnkcase breather with a tube between the valve cover and the air cleaner housing. This insures that only clean air goes into the carnkcase and if an old motor's crankcase pressure exceeds the suction of the PCV valve, the gases are pushed back into the intake rather the out into the atmosphere. Thus the little filter you see in the air cleaner actually servers two purposes. First it insures that no trash will enter your carnkcase and it slows down the introduction of oil into the air cleaner if you develop a positive crankcase pressure. That's why you need to inspect and clean it regularly. The PCV valve is mounted elsewhere like 'below the power steering pump and behind the altenator and is plugged into it's own seperator that attaches to the front timing cover '.

The newest Nissian I have is an 01, so I can't say if Nissian no longer recommends replacement of the PCV valve as a scheduled maintenance item.


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## pir8 (Dec 1, 2005)

Hey,

I don't have the pcv filter thing in the air cleaner housing, just the pipe like oldnissangy said.

I tried looking for it last night but got pulled away by the kids. I'll take a good look at it tonight.

I do know what you are talking about with the aux breather. My 76 cadillac has the pcv off one valve cover, and the breather cartridge running off the other vavle cover. Ahh, when things were simple and easy to get too...

I'm sure this new style pcv is there. But, why doesn't nissan recommend changing it regularly?

M


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## pir8 (Dec 1, 2005)

Correction.... My pcv filter thing is missing! thats why its not there. geeze....


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## Flyingbanana (Jul 27, 2007)

I just replaced mine on my '01 4cyl Frontier after 100,000K. Gave up trying to change it at 60K. Had to take out the alternator from underneath and then we could barely see it and reach it. It's in this black plastic housing that feeds into the block. It took about 3 hrs to replace. Good luck


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## frontera99 (Jul 3, 2005)

My local Nissan dealer/service manager told me he has never had to replace one on any fronty dating back to 98 model year.


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