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  #1  
Old 10th September 2013, 09:53 AM
3.7 slp 3.7 slp is offline
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Default Testing PCV valve

Hi all

just needed some help with the old girl.What i'm getting on the 1st start up is the revs fluttering up and down for about 10 secs before it settles down. I have cleaned the TB and also the PCV Valve which was changed at the start of the year.
I have also given the MAF a clean too. The car seems to run fine once on the moving .Is there a easy way to test the PCV Valve, I have blocked the top pipe on the unit and sucked/blowed on the lower one and i can hear the diaphragm open and close. Is this normal as what it mean to do.

many thanks all for the help
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Old 10th September 2013, 08:39 PM
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Goran Goran is offline
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Check out quattroworld, lots of PCV posts there. Its really very simply made, just a orange rubber diaphragm in a two-piece plastic casing, and a return spring. Its easy to dismantle.
I can only think of two reasons why it wouldnt work:
1. its so clogged up with caked oil the diaphragm cant move properly
2. the diaphragm is punctured or disintegrated

http://forums.quattroworld.com/a8/msgs/80088.phtml

http://forums.quattroworld.com/a8/msgs/79849.phtml

Here is a post with a picture:

http://forums.quattroworld.com/a8/msgs/70936.phtml
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  #3  
Old 2nd September 2018, 03:39 PM
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27litres 27litres is offline
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Warning, old thread revival!

Interesting...
I've been having PCV issues since replacing mine earlier this year.
Oil smell I had seems to have gone, and the car seems to run well, but I've got an awful groan/honk noise.

Gorans links to QW proved to be something I had read before, but made for a good refresher.
I wish I had cleaned the old one just at the moment! And if course now I can't find it!
Might pinch the Silver '02s valve or try the WD40 down the nozzle trick...

Does anyone know why the cheaper/aftermarket PCVs are so troublesome on the 40V engines?



Also I've checked Bentley, the tech dump, online ETKA (realoem.com) and Jim Ellis parts and nothing seems to have much of a breakdown of the operation of the PCV system.
There's no trouble shooting or explanations and incomplete exploded diagrams. It also looks as though the breather system gets confused with the upper engine oil retention system, as that's where the incomplete diagram is found...
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Current:
2001 Audi S8 - Brilliant Black with Black interior, C5 RS6 rims (whenever I actually put them on...), Solar Sunroof, Tinted side and rear glass, RNS-D, Grom, Bose, clunky old phone in arm rest!
2002 Audi S8 - Project
Replacement head coming arrived thanks to MJ
Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
Family:
2009 Volvo XC90 V8 R Design
- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

Sold:
1997 Audi A4
- Hamilton's Club Sport, Achat Grey (will miss the old girl)
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  #4  
Old 2nd September 2018, 03:50 PM
HPsauce HPsauce is offline
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I recall taking the PCV out and cleaning it ages ago, can't even recall if it was this or the previous S8....
BUT it's dead easy to do and easy to get at.

IIRC once I'd taken mine apart and cleaned it up I found a tear on the edge of the orange diaphragm. After cleaning and reassembly it seemed to work OK (tested by sucking and blowing on the various orifices!) but I replaced it anyway.
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2003 D2 FL S8. Irish Green Pearl/Beige. Solar sunroof, auto-dim mirrors, electric rear seat functions, ski hatch retrofit; extended leather. Aftermarket DVB-T, reversing camera and full XCarlink (Bluetooth etc.).
2016 Volvo V40 T5 Cross Country (4WD) with ALL the toys including adaptive cruise etc. etc. Osmium Grey with Blonde/Charcoal leather interior. Polestar performance "optimisation". (A much rarer model than a D2 S8 by the way!) Oh, and a brand new engine at just under 30,000 miles on the factory one!
Finally: gone, but not forgotten.....
1998 D2 PF S8. AgateGrey/Platinum. Every option (I think) except electric rear seats, tiptronic steering wheel, ski hatch, towbar & dimming door mirrors.
e.g. Cruise control, NavPlus/TV, Bose, GSM, Xenons, Solar roof, Parking sensors, Alcantara/leather everywhere of course. (internal dimming mirror added later)
1998 (very early) Ford Focus 1.8 Zetec; ABS/TCS, Heated screen/mirrors, Aircon, Auto-dim mirror, Leather, Trip computer, Cruise control, OEM Ford SatNav with CD changer.
And before that a lot of Rover 800s, a few oddities, a lovely Triumph Dolomite 1850HL with Overdrive and way back in my schooldays an Austin Seven aka Mini 850!
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Old 2nd September 2018, 03:55 PM
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27litres 27litres is offline
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Thanks Andrew,

I'm actually on my third valve and scratching my head!
The second valve was a Meyle (should be quality replacement), so I might open that one up and take a look while its sitting on the bench...

Did you replace with OEM?
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Cheers

Marty


____________________
Current:
2001 Audi S8 - Brilliant Black with Black interior, C5 RS6 rims (whenever I actually put them on...), Solar Sunroof, Tinted side and rear glass, RNS-D, Grom, Bose, clunky old phone in arm rest!
2002 Audi S8 - Project
Replacement head coming arrived thanks to MJ
Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
Family:
2009 Volvo XC90 V8 R Design
- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

Sold:
1997 Audi A4
- Hamilton's Club Sport, Achat Grey (will miss the old girl)
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  #6  
Old 2nd September 2018, 04:16 PM
HPsauce HPsauce is offline
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Quote:
Originally Posted by 27litres View Post
Did you replace with OEM?
I think so.
Even kept the old one as an emergency spare as the damage was so close to the edge seal that I reckoned it was probably going to be OK for temporary use, with a bit of suitable adhesive on the tear.
__________________
2003 D2 FL S8. Irish Green Pearl/Beige. Solar sunroof, auto-dim mirrors, electric rear seat functions, ski hatch retrofit; extended leather. Aftermarket DVB-T, reversing camera and full XCarlink (Bluetooth etc.).
2016 Volvo V40 T5 Cross Country (4WD) with ALL the toys including adaptive cruise etc. etc. Osmium Grey with Blonde/Charcoal leather interior. Polestar performance "optimisation". (A much rarer model than a D2 S8 by the way!) Oh, and a brand new engine at just under 30,000 miles on the factory one!
Finally: gone, but not forgotten.....
1998 D2 PF S8. AgateGrey/Platinum. Every option (I think) except electric rear seats, tiptronic steering wheel, ski hatch, towbar & dimming door mirrors.
e.g. Cruise control, NavPlus/TV, Bose, GSM, Xenons, Solar roof, Parking sensors, Alcantara/leather everywhere of course. (internal dimming mirror added later)
1998 (very early) Ford Focus 1.8 Zetec; ABS/TCS, Heated screen/mirrors, Aircon, Auto-dim mirror, Leather, Trip computer, Cruise control, OEM Ford SatNav with CD changer.
And before that a lot of Rover 800s, a few oddities, a lovely Triumph Dolomite 1850HL with Overdrive and way back in my schooldays an Austin Seven aka Mini 850!
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  #7  
Old 3rd September 2018, 10:09 AM
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27litres 27litres is offline
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This is the best picture of the system I've found.

I'll take a look on the car shortly to see where the hose #10 attaches. I'm thinking it might attach to the venturi suction pump that goes into the intake elbow, but I'm not sure yet

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Cheers

Marty


____________________
Current:
2001 Audi S8 - Brilliant Black with Black interior, C5 RS6 rims (whenever I actually put them on...), Solar Sunroof, Tinted side and rear glass, RNS-D, Grom, Bose, clunky old phone in arm rest!
2002 Audi S8 - Project
Replacement head coming arrived thanks to MJ
Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
Family:
2009 Volvo XC90 V8 R Design
- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

Sold:
1997 Audi A4
- Hamilton's Club Sport, Achat Grey (will miss the old girl)
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  #8  
Old 25th September 2018, 10:51 PM
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27litres 27litres is offline
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Just an update on this:
I sprayed some WD40 down the venting nozzles if the newer PCV on the car.
Initially it quieted down a little, but still had a regular (muted) 'honk'. Over the next couple of days it all disappeared though, so for now I'm happy



Note: on the diagram I posted above, number 10 hose plugs into the top of the valve cover at the rear of the left hand head. PCV function mystery continues....
__________________
Cheers

Marty


____________________
Current:
2001 Audi S8 - Brilliant Black with Black interior, C5 RS6 rims (whenever I actually put them on...), Solar Sunroof, Tinted side and rear glass, RNS-D, Grom, Bose, clunky old phone in arm rest!
2002 Audi S8 - Project
Replacement head coming arrived thanks to MJ
Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
Family:
2009 Volvo XC90 V8 R Design
- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

Sold:
1997 Audi A4
- Hamilton's Club Sport, Achat Grey (will miss the old girl)
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