How important is the PCV?

[Tailfin]

Ok I guess it is that simple lol... I didn't have a specific car in mind, but I'd like to try it on an old engine and see what performance differences and maintenance differences I noticed....presuming I could afford spare cars as a hobby .

I was just afraid that simply sticking it in like that would affect the vacuum system of the vehicle...but I guess it's not too much to worry about...

[ewill3rd]

Atmospheric pcv systems have been around since the early 60's I think.
Vacuum systems were in place before the 70's hit.
Not sure of the specific years. Some quick research could probably reveal exact dates.

[Night Wolf]

performance benifits?

I don't think there are any performance benifits from a PCV system alone... but it really helps to keep engines clean... which inturn can help performance....

On my '79 when I put the open element air filter on, the part where it got air from the air cleaner was no longer there, so I bought a breather filter that went on the valve cover, like a little air cleaner... I suppose that is doing the same thing as the stock system....

[bobbarker]

Originally Posted by FredMaxwell

How important is the PCV?

The importance of the PCV system is to allow air to be drawn through the crankcase to carry impurities including corrosive chemicals out of the crankcase and into the intake (NOT GOOD since it will eventually clog up your intake and reduce power). When the engine is getting a bit old, the crankcase breather also acts to allow the fuming to get out. On a tired engine, the PCV will be able to draw vapours and air through the crankcase at idle, but the breather will let stuff out at higher throttle openings. As the engine becomes more stuffed, the point at which PCV can draw air in spite of the blowby will get closer and closer to idle...

[davew26]

This sounds like my STS. Does anyone know where I can find the PVC valve on a 93 STS. The idle is driving me crazy.. Idles at 1600 in neutral. Last week it was a nice 700 rpm idle.

Great site.

Thanks.

Dave

[Tailfin]

http://www.rockauto.com/catalog/cata...&parttype=5052

But this is a cheap and common part, so I'd just go to Advance Auto, NAPA, whatever and they should have one.

[Jim Ellis]

Good answer ............... Do you know where the PCV Valve is located in a 2004 DeVille engine (NorthStar)?

[awadecki]

Hi Jim--

Wrong posting area (see Northstar forum), but I believe it's in the rear valve cover.

[Jim Ellis]

Thanx!!!!!!!

[ewill3rd]

Most newer N* engines no longer have a serviceable PCV valve.
It is a fixed orifice that is actually part of the valve cover.
I can't remember what year they switched over to this. I think it might have been '02 or maybe '04?

I can't really think of any newer Cadillacs that still use a PCV valve. Most of them are fixed orifice types these days.
Even the Escalade and the CTS-V engines have a "valve" but it is really a hollow valve body with a hole drilled in the bottom.

[z06bigbird]

You could get rid of it, and be at risk for a $10,000 fine. Me too if I had suggested getting rid of it.

I don't know how you would get caught, but others should have some war stories on this.

[ewill3rd]

It is not something that you would really want to get rid of.... it serves an important purpose, to remove it is to invite oil leaks and all kinds of other problems.
Technically it is an emissions control device and subject to fine for tampering.