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OBD2 PCV INLET VALVE "COMMON FAULT??" INFO 4 U


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Ok...apologies for length and apologies if already posted but i may be able to save u a few ££ in the process !.....I spotted an apparent "common fault" on my vr6 (fault posted on a few websites in past anyway)...Involves one of my air hoses leading from throttle housing to top left of my OBD2 engine crankcase with a small valve called a p.c.v linked in-between it (see pics attached below). [im img] g]

This little baby has split at the pcv valve, this is moulded black sealed plastic an has perished and split thus causing air and oil residue to blow out.

This can alledgedly, be stripped and cleaned and diaphram replaced as part of your "home tuning" hobby to aid engine breathing and fuel efficiency however as in my case and many others you will have to or prefer to purchase a new pcv valve/hoses/attachments.....Now this is where it gets tricky as I managed to find a few sources on the web ranging from £54 to £135 including or not including extra air hose attachment or just the pcv valve....even a chap on ebay wanting £34 for his "as new" pcv valve only .... or with air hose for extra £12 not inc p&p...as i write this (23/05/08)!

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=140234433956&_trksid=p3907.m32&_trkparms=tab%3DWatching#ebayphotohosting

If you pop to vw dealers and quote part number :3A0129615E they will charge you £74.50 ex vat!!! however they say this has been deleted from stock and no replacement has been issued, anyway this vw part is, as usual more than umay need ie; lots of pipes , the required pcv valve and other bits n pieces to try to justify this small problem with their massive cost!!

Now if its just a split valve like mine (common fault) then write this part number down and pop to your local FORD dealer ...yes u read correctly!....: FOR 7364573 :valve assembly for a galaxy v6 circa 1996-onwards. The engine in it is our beloved VW 2.8efi v6. Cost : £26.89 includes the vat.

Now also on my search many vr6 owners suggest replacing such faulty item with a "catch tank" ie; removing the pcv inlet valve altogether and clamping hose from throttle housing pipe and placing some small container to other pipe leading from cranckcase to collect the reside oil from vapour exhausted out!.....mmmmm tricky when u think that the pcv is there for a reason and i believe it assists the fuel/air mixture via the engine ecu amongst other things!! mpg out window time me suspects, but im no expert on this one.

Sooooo if its just to clean/replace for piece of mind or indeed as in my case you stumble upon its fault then pop to ford and not vw to save yourselves the £60 inc vat or more and potentially improve ur mpg which is a brucie bonus lol..... pm me if u want further info on this if u wishok & good luck!

pics 1 & 2 are my oily split pcv

pic 3 is whole assemble for sale as seperate parts on ebay but also on other parts sites inc vw dealer

pic 4 is pcv valve that ford sell seperate

1211556525_7119_FT0_photo-0067_.jpg

1211556525_7119_FT0_photo-0068_.jpg

1211557785_7119_FT0_air_flow_pipe_with_pcv_intake_valve_attached_vr6.jpg

1211557785_7119_FT0_pcv_air_intake_valve_vr6.jpg

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My PCV has been busted for ages. I decided to go down the route of a catch can, primarily because I see it as a more permanent fix. Although a catch can needs emptied periodically, that's a two-second job whilst your checking your oil and other fluids anyway.

If you replace one crappy PCV with another, you'll be hunting for it again in another few years (and the price is going to go up the rarer these parts / cars become). Most cars of the Mk3 Golf / Corrado era will have had a replacement PCV anyway - so most of us are now replacing the PCV for the second (or third) time. I wouldn't accept a used PCV because they are so prone to failure. It's a gamble as to whether a PCV with (e.g.) 70k on it - which isn't currently busted - isn't going to be spewing crud down the side of your engine before it reaches 80k.

As for the original poster's comments regarding fuel economy, I'm inclined to disagree. Although I'm not doubting that the PCV is there for a reason, mine's been absolutely buggered since I got the car and my fuel economy seems to be on a par with other members (approx 32-35mpg on motorway journeys at 70mph). Unless someone's about to prove me wrong with their 40mpg+ Golf VR6, I don't expect to see any dip in fuel economy by deleting the PCV entirely and replacing it with a catch can. Saving your throttle body from drinking sooty black oil can't be a bad thing either, IMO.

The cost difference between replacing the PCV with a new one or a catch can appears to be minimal as well. PCVs seem to be about £40-45 (as of May 2013), whilst a catch can (plus all associated brackets, hoses and clamps) cost me £40. The fitting difficulty is about the same for both parts (easy).

I'd be interested to hear what other people think about the catch can vs. PCV???

p.s. - Once I've completed the job, I'll try and remember to post a guide as to what I've done. I'll also report back on the fuel economy situation - however, as I've never had a working PCV, I can only compare a busted PCV to a catch can.

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My PCV has also been busted forever so it would nice to see a fresh write up on this and your findings.

its one of thos jobs im "getting round too" :)

also as i have a port polished TB itd make sense to stop sending oil and cack back through it

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Basically, the PCV allows blow-by gases from the crankcase to escape. It re-routes them back towards the intake manifold, where they are sucked into the engine and burnt. This more complete burning of the gases them means overall hydrocarbon emissions are lower than if the gas (and associated crud) were allowed to escape first time.

Disconnecting your PCV should have no impact on the running of the engine (I THINK - feel free to correct me), as it is just providing a route for waste products of the combustion process to escape (and my one has been totally busted for 2 years, with no major side-effects that I can detect). In the past, these waste gases (and oily muck) were simply allowed to drip out of the engine (venting to atmosphere). Catch cans were used (at least) since the 1920s on some sportier models, and PCV valves became standard practice at some point in the past 30-40 years.

The benefits of a PCV are primarily that it deals with the waste gases (from an emissions perspective) without the need for continued user maintenance (i.e. emptying a catch can periodically).

I was split between replacing the PCV and going with the catch can. I've opted for the catch can due to my perception that the OEM PCVs used on AAA VR6 engines are of questionable build quality. However, as Pete mentioned (above), maybe this isn't as much of an issue as I think it is. But I've bought the catch can now, so that's what's being fitted!

The inside of my throttle body was covered in oily muck, as was the intake manifold. I don't know if this is to be expected from a fully-functioning PCV also? But the main reason for me changing it now was that the oil was leaking down the side of my engine, not only making it unsightly but starting to collect in the #1 spark plug well.

Will post a guide once done.

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