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Callmewhitexr7
08-24-2004, 10:42 PM
Ok I got a pcv valve from autozone and put it on my car, it made the car idle alot better, but about a week later the car began to idle very crappy and rough, so i replaced the pcv valve again with one from autozone and this fixed the idle. so my ? is do the autozone pcv valves have a problem that makes them mess up and why would this fix my idle? Also everytime I seem to post on this board no one answers any of my posts, I try to answer other posts to help out everyone, but why does no one answer my post? thanks


NICK

Billabong089
08-24-2004, 10:45 PM
maybe no one has answers to your questions?


I looked this up for you.


Positive Crankcase Ventilation (PCV) System

The Positive Crankcase Ventilation (PCV) System (Figure 1) cycles crankcase gases back through the engine where they are burned. The PCV valve regulates the amount of ventilating air and blow-by gas to the intake manifold and prevents backfire from traveling into the crankcase. The PCV valve should be mounted in a vertical position (Figure 1). On some engine applications, the PCV system is connected with the evaporative emission system.

Do not remove the PCV system from the engine. Doing so will adversely affect the fuel economy and engine ventilation with resultant shortening of engine life.


AND

Positive Closed-Type Crankcase Ventilation System

A malfunctioning closed crankcase ventilation system may be indicated by loping or rough engine idle. Do not attempt to compensate for this idle condition by disconnecting the crankcase ventilation system and making an air by-pass or idle speed adjustment. The removal of the crankcase ventilation system from the engine will adversely affect the fuel economy and engine ventilation with resultant shortening of engine life.

Billabong089
08-24-2004, 10:49 PM
and Diagonistics:

VALVE CHECK


NOTE:
Set parking brake and block wheels. Place transmission/transaxle in NEUTRAL or PARK. Place the A/C-Heat selector in the OFF position.

l Remove PCV valve from rocker cover grommet (for 5.0L cars, the PCV valve is located on top of block by firewall).

l Shake the PCV valve.

l Does PCV valve rattle when shaken?

Yes
REINSTALL PCV valve. GO to «PCV2».

No
PCV valve is sticking.
REPLACE PCV valve.

________________________________________



PCV SYSTEM CHECK


l Start engine and bring to normal operating temperature.

-- Disconnect hose from remote air cleaner or air outlet tube (tube connecting mass air meter and throttle body).

-- Place a stiff piece of paper over the hose end. Wait one minute.

-- Does vacuum hold the paper in place?

Yes
System is OK. RECONNECT hose. GO to «Section 2A» for other possible causes of vehicle symptoms.

No
System is plugged or Evaporative Emission Valve is leaking (if equipped). GO
to «PCV3».


_________________________________


PCV3 EVAPORATIVE EMISSION SYSTEM CHECK


l Disconnect evaporative hose (if equipped), cap the connector and retest.

l Place a stiff piece of paper over the hose/nipple, as in PCV2. Wait one minute.

l Does vacuum hold the paper in place?

Yes
GO to Evaporative Emission System, «Section 11A».

No
CHECK for vacuum leaks/obstruction in the system: oil cap, PCV valve, hoses, cut grommets (oil separator on 2.3L HSC, 2.9L and 4.9L engines) and rocker cover for bolt torque/gasket leak. SERVICE as necessary.

Callmewhitexr7
08-24-2004, 11:58 PM
Thanks but is there a reason to why the autozone pcv keeps messing up? Thanks



NICK

J.D.
08-25-2004, 12:23 AM
Could be a bad batch. Try a different make.
Does the bad PCV valve rattle (as Billabong089 suggested)? Is it extremely oily?

Billabong089
08-25-2004, 01:32 AM
well no one manufactured Autozone's PCV HERE, so I dont think anyone can answer your question, go to Autozone, tell them it doesnt work, you would like your money back. Take your money and get it some where else. Problem Solved.

XR7 Dave
08-25-2004, 09:33 AM
The Ford ones are the only ones that work properly. A supercharged motor builds crankcase pressure under boost and the Ford ones are the only ones what will positively seal stopping crankcase pressure (and lots of oil) from getting into your intake plenum. A good valve should only pass air when under vacuum. No aftermarket PCV valves are any good for our motors.

blue94sc
08-25-2004, 01:06 PM
The Ford ones are the only ones that work properly. A supercharged motor builds crankcase pressure under boost and the Ford ones are the only ones what will positively seal stopping crankcase pressure (and lots of oil) from getting into your intake plenum. A good valve should only pass air when under vacuum. No aftermarket PCV valves are any good for our motors.
Hey Dave.
Are the Ford PCV Valves a dealer only part, or can they be purchased from other distributors (on-line)?
LMK
Thanx
Bill

Joisey Jim
08-25-2004, 01:20 PM
Dave's right, it's amazing how sensitive pcv valves are. So buy the Motorcraft EV 145 and move on. Even on my '91 Escort GT (1.8 DOHC) the valve cover would leak using the Purolator pvc. Went back to Motorcraft, no problem.

darkstar_one
08-25-2004, 02:24 PM
i put a check valve on my AUTOZONE PCV thingy, well now this question, is that metal tube that connects the tube to the plenum and to the extra hose and to the PCV necessary? can i just put a T FITTING because ever since i changed the valve i cant seem to line it up straight, thanx

Jeremy_K
08-25-2004, 02:55 PM
i put a check valve on my AUTOZONE PCV thingy, well now this question, is that metal tube that connects the tube to the plenum and to the extra hose and to the PCV necessary? can i just put a T FITTING because ever since i changed the valve i cant seem to line it up straight, thanx

yeah, mine won't line up either. it gets in the way of my tranny dipstick. :mad:

Callmewhitexr7
08-26-2004, 01:24 AM
yes the PCV valve rattles alot and its oily when i take it out. I'm just going to get one from ford cause now my cars acting up again and just changed it a few days ago. Thanks for all the help. Also what does it mean when it rattles alot and is oily?


NICK

v8killr
08-26-2004, 02:53 AM
I don't know if you know it or not but there are two of them on our cars.
Dave

darkstar_one
08-26-2004, 03:06 AM
yes but only one closes under boost the other one is just empty. doesnt close, just stays open

SCvidar
08-26-2004, 04:24 AM
Hi all.
Dave is right, this is from an old post by Rob:

"Some oil in the intake from the PCV system is a common thing on these cars. Especially if the PCV valve has been replaced with an aftermarket one - Ford has a special valve for the SC that supposedly works best, it's only a couple bucks from Ford.
Rob
'91 Ford Thunderbird SC"
Vidar.

Micahdogg
08-26-2004, 03:34 PM
How are there two PCV valves on our cars?

Micah

XR7 Dave
08-26-2004, 04:15 PM
I keep an extra one in my glovebox just in case. ;)

J.D.
08-26-2004, 11:41 PM
yes the PCV valve rattles alot and its oily when i take it out. I'm just going to get one from ford cause now my cars acting up again and just changed it a few days ago. Thanks for all the help. Also what does it mean when it rattles alot and is oily?


NICK

One symptom of a defective PCV valve is if it doesn't rattle. It should be oily because of the oil fumes that it's supposed to vent. From experience I know that it should be somewhat oily - so if it is very oily I would suppose that something is wrong. In addition, if it is very oily then it will get clogged and stop working. If anyone has a more scientific explanation, please help out.

Callmewhitexr7
08-27-2004, 12:05 AM
hey everyone I appriciate all the help. So theres two pcv valves on the car? were are they located at? Thanks again for the help


NICK

darkstar_one
08-27-2004, 12:10 AM
they both are located on each valve cover, the one on the passenger u need to replace it with a genuine motorcraft one and the one on the dirvers side can be replaced with a EL CHEAPO one.

J.D.
08-27-2004, 01:08 AM
I understood from the previous posts that the "2 PCV valves on an SC" is a joke. As far as I can recall, my car has one PCV valve and on the other valve cover there's a fitting that only looks like a PCV valve.

darkstar_one
08-27-2004, 01:13 AM
ha ha ha, thats very funny, u should be doing comedy. :p

J.D.
08-27-2004, 02:04 AM
Thanks for the compliment, but I was serious. I'll check my car when I get home tomorrow night.
Anyway, why would Ford install two PCV valves when it can save a couple of bucks per car by using one valve and connecting the two valve covers with a tube?

Micahdogg
08-27-2004, 10:54 AM
The drivers side cover is just a vent. Nothing more than a hole in the cover with a tube that should lead to the rubber intake tube so that the driver cover can pull in fresh filtered air.

Of course my drivers cover is breathing in non filtered air and all is well since 2000. Maybe my oil gets a little dirtier, but I change it often.

Micah

darkstar_one
08-27-2004, 12:11 PM
i thought the drivers side also pushes air out, as in the intake is sucking air in from the drivers side valve cover? or is it sucking it in? i think the intake sucks air out of the drivers side because i had my intake dripping with oil a while back, and it was comming out of the hose connector. not that it matters.

did u replace ur grommet also?
did u alignt the damn lil metal PCV tube? i coulnt, can it be eliminated? is it necessary?

Jeremy_K
08-27-2004, 12:32 PM
i would think that using the venturi effect, the intake air rushing through the tube would pull vacuum from the driver side valve cover. does anyone know what the hell that vent does on the driver side? is it just one more thing we can yank outta there to get out of the way? i'm sure someone knows what it does. :confused:

Micahdogg
08-27-2004, 12:49 PM
The PCV draws oil vapor out of the crank to be recycled through the engine. Weather it is for emmissions, prolonged life of the motor, increased gas mileage? or all of them I don't know....but we know that the PCV valve in the pass side cover flows vapor OUT of the engine. Therefore, the "breather" tube coming from the drivers side cover is probably not going to also pull vapor OUT of the engine. Rather it I would assume that it simply breathes air to eliminate a conflict of pressure and to assist in the PCV operation. You might find under different rpms and positions of the PCV that air could flow in and out of the drivers cover as it is simply "breathing".

The only reason for a tube running all the way to the rubber intake is so that as it breathes....it will be breathing fresh filtered air and not "dirtier" air from the engine bay. Ford could have just put baby filter on that valve cover, but it would not be as compact and the system would become higher maintanence as you now have another filter to keep clean.

I removed the tube running across the motor and simply have the rubber gromett with the stock 90 degree plastic fitting sticking out. There is no filter, it's just a one inch piece of tube that comes out at a flush 90 from the cover. I might put a fitler on it one of these days, but my motor has 100K miles on it and frankly, unless it's digesting rocks or something....I'm not worried.

Now when I rebuild the motor I'm sure I'll put a baby K&N on there. But no, your motor won't blow up or self destruct if you remove that tube.

Micah

Micahdogg
08-27-2004, 12:54 PM
Oh, and I should add that you shouldn't go removing the tubes if they are working fine. I mean, there is no performance to be gained or lost here. My tube had fallen off and in a failed attempt to secure it back I just decided to leave it off as I didn't think it would have any MAJOR adverse affects.

In the end, it's your call....but at the time I was also trying to eliminated unnecessary items under the hood for a cleaner look and this fell in that catagory.

Micah

Jeremy_K
08-27-2004, 05:51 PM
can you feel any suction or pressure from that tube on the driver side?

lilredstang
03-07-2006, 09:25 PM
Ok I got a pcv valve from autozone and put it on my car, it made the car idle alot better, but about a week later the car began to idle very crappy and rough, so i replaced the pcv valve again with one from autozone and this fixed the idle. so my ? is do the autozone pcv valves have a problem that makes them mess up and why would this fix my idle? Also everytime I seem to post on this board no one answers any of my posts, I try to answer other posts to help out everyone, but why does no one answer my post? thanks


NICK


GET ONE FROM THE FORD DEALER ITS AN "EV-145" AND IT WILL SEAL UNDER BOOST LIKE IT SHOULD. THE AFTERMARKET REPLACEMENTS DONT AND YOU END UP BOOSTING THE CRANKCASE TOO!!! THEY ARE ONLY $5.**

bloodybobber
03-08-2006, 12:31 AM
The line crossing the engine to the intake pipe from the drivers valve cover allows filtered and metered (MAF sensor) air to be used to evacuate the oil fumes from the crankcase thru the PCV valve. The PCV valve controls how much air is drawn from the crankcase. If that line is disconnected you create a non metered air leak at the intake tube that may cause a lean mixture condition. Catch you later, Bob.

Jeremy_K
03-08-2006, 06:17 PM
It's funny that this thread just popped up again. I just went from the baby valve cover filter back to the original vacuum line to the intake pipe the other day. I haven't noticed a difference either way. I had the breather filter on there for over a year with no problems. I just don't like that vac line running across the engine. I may eventually go back to the breather once I get a chance to clean it.

90coug
03-08-2006, 07:42 PM
Hey Dave.
Are the Ford PCV Valves a dealer only part, or can they be purchased from other distributors (on-line)?
LMK
Thanx
Bill

You can find them at RockAuto

ilusnforc
12-29-2006, 01:24 PM
I just placed an order at www.rockauto.com this morning for a Motorcraft EV-145 pcv valve, shortly after they called and said it was discontinued and they will be updating their site to reflect that. They offered to exchange with an AC Delco or some other brand instead but I declined and asked for a refund (I can buy those locally). Does anyone know where I can get a Motorcraft EV-145 pcv valve? Thanks!

lilredstang
12-29-2006, 02:06 PM
For a couple of weeks I used the OEM PCV from my turbocharged 2.3L mustang(1984-1986 mustang SVO). It was just a tad bit taller, but it sealed under boost just like the ev-145, so it work fine. You may also be able to use a PCV from a supercharged 2003-2004 mustang cobra or the supercharged F-150 lightning truck. The EV-145 was discontinued a few months back. I wouldnt be suprised if the SVO PCV has been discontinued too.

x182dan
12-29-2006, 06:38 PM
sorry but I didn't read the whole thread just the first part. Don't put autozone crap on your car please. Cheap crap if you ask me. Go spend the $2.00 more and go to some higher end parts store. I only go to autozone if I need oil or something like that

Scott Long
12-30-2006, 09:23 PM
I know the PCV line can cause a vac leak and that will affect the idle.

I also thought that having the line unhooked to the intake would suck in a small amount of unmetered air that could cause a lean condition. On my car that might help lean it out.