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PVC Valve

4K views 49 replies 8 participants last post by  Still Pete67... 
#1 ·
I have a 94 900se 2.5 and cannot seem to locate the PVC valve. I am not getting any vacuum to the fuel pressure regulator and need to check and see if there is vacuum going to the PVC valve. Any help would be appreciated.
 
#2 ·
A V6 ?

No pics have I:cheesy:
This will take some hunting.
I think the PCV system will run between the cam cover (one of them) and the throttle body, if this 6 is similar to the 4...
 
#6 ·
gthomp0805 said:
Now I am told by the dealer there is no PCV valve just a check valve between the trottle body and the charcoal canister. They want 78.00 for the valve. Wow. What a rip. eeuroparts has it for 10.00 or 16.00.
1) That is the evap canister purge valve, nothing to do with crankcase ventilation. Easy to check if it is leaking vacuum, cap the line off with a rubber cap from any part store, and check the vacuum before and after.

2) The 3.5L V6 DOES have a PCV valve/filter, the crankcase ventilation system is GM, and completely different from any of the 4-cyl engines. Assuming it is faulty, which is not common, I doubt eEuroparts has it for $10, it is a fairly complex part compared to the turbo PCV check valve, GM list price is around $150.

3) The original p/n's for the V6 are as follows:

Article : Crank case ventilation
PartNo : 4504882
Usage : 1994, NLS-USE 4770160

Article : Positive crankcase ventilation valve
PartNo : 4770160
Usage : 1995-1997
 
#8 ·
gthomp0805 said:
I appreciate this information. thesaabsite has it for 143 and change. Do you know why I would not get vacuum to the fuel pressure regulator? There are 2 ports coming off of the throttle body. One goes to the regulator the other is capped.
I don't know the V6 well enough. I think Ragtop is the resident expert or close to it.

I don't think I would just start swapping parts on a guess.

On the 4-cyl I would first test, or just replace the hose to the FPR. Then I would remove the other TB connections one at a time, and temporarily cap the ports while measuring the vacuum at the FPT using a gauge and T off the line etc...

The evap canister purge valve can be tested, I do know that, but I do not know anything about the V6 PCV system testing. On the 900 turbo, most vacuum leaks are from cracked hoses, example:



This was part of the FPR hose from a 900 Turbo, obviously, a hose will not hold vacuum in that state.
 
#11 ·
There is no hose off the intake manifold. There are 3 off the throttle body, one goes to the IAC valve, one to the fuel pressure regulator and the other to a check valve which then goes into the fire wall to the charcoal canister. There is no PCV valve on a V6 so finding this crankcase breather housing has been quite a chore. Ah, unless the charcoal canister and the crankcase breather housing are one in the same. Can someone confirm?
 
#12 ·
In this context, the throttle body and inlet manifold are a common source of vacuum. The older Saabs used ports on the intake manifold.They can be anyplace where an adequate vacuum is generated...

To find the PVC(positive vented crankcase) valve system, you may well have to remove the intake(inlet) manifold (same as when changing the 3 rear plugs)....
This is conjecture on my part; but the PCV exists, if it is not in the open, then one must "dig" for it....
 
#14 ·
Have patience.

Repost this as " V6 PVC valve, where is it ?" Ragtop or Diosnoche, or PMI, are bound to respond....

Why pay the dealer $100 just to find it ???
 
#15 ·
I have been trying to get this fixed for about a week. The car in general has run crappy since I bought it in Aug. I am trying the least expensive routes first as anyone else would. I am getting 8MPG. ugh! PMI has responded that he is not that familiar with the v6. Funny, I called the dealer about the PCV valve and the parts guy did not even know the v6 does not have one. He kept putting me on hold and going back to the service department to make sure I knew what I was talking about. Havent heard from the other 2 gents and I am running out of patience. Sorry, I never had much to begin with.:D
 
#16 ·
PMI is honest. The Saab dealer has sold 3 V6s over the past 3 years(explaining why their knowledge is limited);parts-men (far too many) know nothing, and are not well paid; the smarter men are busy selling the Saab turbo...:cheesy:

Repost this as " V6 PVC valve, where is it ?" ....
BTW, I doubt is the PVC has very much with the poor running, but of course it should be examined..
And I hope you do have a warm garage...
The Saab V6 is a rather rare bird - thus, patience is a must...:cheesy:
 
#17 ·
And I appreciate the honestly and nothing less. I suppose you are right about the poor running. I suspect that is the tensioner which the dealer never warned me was going bad when they did the timing belt. As for the garage, yes it is heated. LOL. Would have it no other way as I have a 84 318i that my son and I frequently tinker with. I will repost (good idea) and thanks again for your help.
 
#18 ·
gthomp0805 said:
There is no hose off the intake manifold. There are 3 off the throttle body..
I have not worked on the 6-cyl engine. I assumed someone with the same model would pick up the thread. The diagram shows two hoses, not sure where one goes, perhaps the TB. The second hose looks like it drops right down from the bottom side of the intake manifold. Seemed straight forward to follow the hose, but perhaps it isn't, sorry.
 
#19 ·
Hi, the V6 doesn't have any sort of PCV valve system, there is none, so don't waste your time hunting one down on the 2.5L V6 engine.

I once had a photo on here of my throttle body with the 3 vacuum ports and lines, i'll try and find the original for you, if anything I take a new photo of the vacuum lines for you.

But don't bother looking for a PCV valve, there isn't one.

In my opinion, the V6 is a very nice engine, if you understand it. The V6 doesn't demand alot of maintenance, but it does demand respect in the sense that you do the recommended service as outline in its literature (timing belt for example, oil changes with 100% synthetic).

If you're generally having poor MPG, service the Upstream Oxygen sensors, Bank 1 Sensor 1 and Bank 2 Sensor 1, don't worry about the downstream sensors just yet. Clean and inspect the IAC which is located under the intake manifold, inspect and clean the MAF, perhaps get a motorvac done of the fuel injectors and fuel system, change the air filter, change the fuel filter. Use the recommended spark plugs (Bosch FR8LDC) which are the factory plugs and are dual tipped for a dual spark, change the high tension wires. Basically a complete tune up.

Perhaps you could elaborate on what the symptoms are and your problem.
 
#22 ·
So i've taken a two pics of the V6 engine, the photos show the vacuum lines



The bottom photo shows the 3 ports off the TB for the V6 engine.




As you can see from my photo of the above vacuum lines, I plugged off the EVAP system because I was having idling problems about a year ago when I was coming off the highway; the engine began to stumble and sputter like it was choking only after deaccelerating from high speed. I figured out that it was the EVAP system purging the charcol canister of fuel vapours during the deacceleration process. I speculated that the EVAP was purging too much additional fuel into the engine which caused the engine to idle rough.

I've had this hose plugged for about a year now with no ill effects, just excellent performance from the engine since.
 
#23 ·
This is Great!!!! OK now I have the same setup. The middle was plugged as well but the one going to the FPR was not producing and vacuum so I plugged the one on the right and attached the FPR to the middle. Made no diff in the way its running. Why is it that the FPR should have at least 19psi of vacuum to work properly. So without the FPR working the engine runs like crap.
 
#24 ·
I'd open up the intake hose there and see if the ports are clogged or blocked. Use a little intake cleaner or a small brush to clean the ports, they do become gummed up if you have the EVAP lines hooked up from the fuel.

otherwise i'd check that vacuum line to see if its the problem.

You can try to hook up the fuel pressure regulator to the SAI vacuum port and just disconnect the SAI for the time being, it won't affect engine performance if the SAI is removed as well.

If you're still not getting any vacuum, I'd suspect the intake manifold itself. Have you ever had the intake manifold off? If you have, did you replace the intake gasket? If not, and you used the old gasket, did you make sure that the mating surfaces were clean and flat so that the gasket would sit properly. If the intake gasket is leaking then it will cause idling problems because un-metered air will be drawn into the engine and screw up the fuel/air ratio/mixture.
 
#25 ·
I have it open a number of times and sprayed it but not the port itself so I will do this. I will also try moving the FPR hose over and see if it makes a diff. As for the intake, yes I have had it off more than a dozen times but have not replaced the green gasket. I have wiped it down and even tried gasket goop but didnt make a diff. I will buy a new gasket and replace and see if that helps. Thanks again for your help with this.
 
#26 ·
I'd consider replacing the gasket since you've had the top off more than a couple of times now and have reused the same gasket. When you do replace it, make sure to block off the intake ports to the cylinders with rags or similar, then clean the surfaces good, don't scratch them. Don't use gasket maker or sealant, a new gasket is all you need. Then before closing it up, take a shop vac to the area and vacuum all or any dirt and sand from the area, and inside the intake ports in case some fell down into the cylinders.

Close up the intake and, very important, use a good torque wrench and tighten the intake bolts to 15 ft/lbs. Tighten the intake manifold bolts starting with the middle bolts and continue alternately towards the ends.
 
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