Have you replaced your PCV Valve Lately?

[BlazerLT]

Mine is a 1995 and as you can see, it has had better days.

It rattled like it should BUT it still wasn't functioning 100%.

When it was cold, it worked awesome, but when it warmed up, it would stick.

Cost: $2-$3
Time: 2 Minutes

Having an even and smooth idle........PRICELESS.

Guys, if you PCV valve is more than 3-4 years old, replace it.

 

[Farticus]

I assume mine's old, but it's hard to get at and it costs something like 16 bucks at Canadian Tire. My car is a 93 Geo Metro, by the way.

 

[cryptokid]

man i dont even have a pcv valve. i ripped it out along with most of the emissions junk a long time ago.

i run a open road vent instead. no more gunked up intake manifold and valves for me!

 

[baomo]

i don't have a PCV, just a crankcase breather. and i have replaced it. it was $45

 

[Rick in PA]

Good tip. Remember to check the hoses too, they can get gunked-up or collapse.

I believe a working PCV system helps keep the oil cleaner, less contaminated with condensed water & combustion blow-by. The PCV system is especially important in short trip, stop-n-go driving.

 

[Matt A.]

Now - I work for a Chevrolet dealership (so if ya need anything specific for a GM product [Including Saturn] let me know)and GM vehicles seem to be the worst regarding the PCV valves. (very-very finnicky. Had one that wouldn't even stay at idle after it was started - go figure)

Even there is a TSB on the new 5.3 (well, newer) 6.0, ect.. PCV valve for irregular idle/oil conumption. GM vehicles seem to be TOO strict and now allowing enough 'variables' when engineering/designing their engines.

Forget GM - Just gimmie my Jeep!

 

[Terry]

Another good reason to use Auto-RX, LC and FP to control insolubles production that ends up gumming these babies !


Matt A.

to BITOG as a member.

 

[TallPaul]

Both my F150 and my E350 motorhome have the PCV filter in the airbox, but the wife's Aerostar does not have a filter. What's the deal? How does that work? I don't even think there is a pipe from the PCV to the air box. Not modified either.

 

[BlazerLT]

quote:

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Originally posted by TallPaul:
Both my F150 and my E350 motorhome have the PCV filter in the airbox, but the wife's Aerostar does not have a filter. What's the deal? How does that work? I don't even think there is a pipe from the PCV to the air box. Not modified either.

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The PCV valve is isn't in the air box.

It is always in the valve cover.

 

[TallPaul]

quote:

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Originally posted by BlazerLT:
The PCV valve is isn't in the air box.

It is always in the valve cover.

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Right. It is in the valve cover, but the filter typically is in the airbox and the Aero apparently does not have a filter on the PCV system.

 

[tmorris1]

quote:

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Originally posted by TallPaul:

quote:

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Originally posted by BlazerLT:
The PCV valve is isn't in the air box.

It is always in the valve cover.

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Right. It is in the valve cover, but the filter typically is in the airbox and the Aero apparently does not have a filter on the PCV system.

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On newer vehicles the PCV vents into the intake manifold I believe, so it shouldn't really need to be filtered. Their is no place for dirt to get in.

 

[TC]

In the past I've rarely replaced PCV valves, and instead about once a year removed them and ran spray carburetor cleaner through them. Always seemed to keep them working properly, with no apparent problems.

 

[brianl703]

quote:

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Originally posted by tmorris1:
On newer vehicles the PCV vents into the intake manifold I believe, so it shouldn't really need to be filtered. Their is no place for dirt to get in.

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On my 1988 Ford Mustang 5.0, there's a tube from the oil filler neck which goes into the throttle body. That's where the PCV vents.

On my 1996 Ford Contour 2.5, there's two tubes from both valve covers which connect to the air intake duct between the mass airflow sensor and the throttle body. The idle air control valve takes it's air upstream of the tubes from the valve covers, it was designed this way so that the idle air control valve doesn't get sludged up with junk from the crankcase.

I think that PCV valve application is more critical for those systems which (1) use a mass-air flow(MAF) sensor as opposed to a MAP sensor and (2) draw their air from the airfilter box, before the MAF sensor. In those systems the PCV valve is essentially a controlled vacuum leak.

 

[TallPaul]

quote:

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Originally posted by brianl703:
I think that PCV valve application is more critical for those systems which (1) use a mass-air flow(MAF) sensor as opposed to a MAP sensor and (2) draw their air from the airfilter box, before the MAF sensor. In those systems the PCV valve is essentially a controlled vacuum leak.

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This may be the case with the Aerostar 3.0. I noticed once when I took off the oil filler cap with the engine running, it began to run rough like a vacuum leak. Of course that may also be due to the controlled vacuum leak I put in the shift modulator line to firm up the shifting (worked great too!

).

BTW: My Chilton's manual also says "Do not attempt to clean an old PCV valve using solvent or any other cleaning material."

 

[brianl703]

On the Contour 2.5, I hooked up my scantool and watched the long-term fuel trim as I pulled the dipstick out. As soon as I did that, the long-term fuel trim started to increase, meaning that the computer sensed a lean condition and is adding more fuel (over the baseline levels programmed into the computer at the factory). Putting the dipstick back caused the long-term fuel trim to decrease.

Makes sense, since the only air that goes into the crankcase under normal circumstances goes through the MAF first. Pulling the dipstick out allowed air into the crankcase which did NOT go through the MAF, so the computer didn't account for it.

Still, that the computer could detect and respond to the tiny vacuum leak from pulling the dipstick out is just an amazing example of how sensitive these systems can be.