C4P Rocker Cover Crankcase RV

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C4P Rocker Cover Crankcase RV

Post by nilrem » 11 May 2018, 05:35

Morning all
I'm in the process of evaluating my 104,000mls 2007 C4P Exc 1.6 HDi - Checking Turbo wear and oil feed pipe. DPF inspection and repair a leaking injector seal - all with a view ''is it worth keeping'' cos I do like the ride/drive ability.

Started to dissemble things - 1st problem - on removal of the Rocker Cover and the disassemble of the RV. I think it's called crankcase relief valve I noticed splits in the diaphragm at it's crease points, obviously the next Q is are they available as a separate item. cos the Rocker Cover complete is £50-60 - buying used one would I think have the same problem

Q - Can someone explain how the RV works cos it seem that the internal spring keeps the valve open all the time...joe

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Re: C4P Rocker Cover Crankcase RV

Post by RichardW » 11 May 2018, 10:37

It's only available as a complete unit, at nearly £110 now....

Not sure ow it works - I couldn't figure it out when I had mine apart. I suspect it is designed to only allow the vapour out when the turbo inlet is below the rocker cover pressure to prevent overpressuring the crank case when the turbo stalls as you lift off.

If there is no evidence of leaks from the crankcase, I'd just ignore it. These are still work reasonable money (2.5-3k for a 100k mile 08 HDi) so it's worth spending a but on it. You will be approaching new clutch if not already done, and then the DPF light will come on soon, plus the front wheel bearings seem to last about 100k so there might be more work there....

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Joined: 09 Feb 2014, 08:42

Re: C4P Rocker Cover Crankcase RV

Post by nilrem » 11 May 2018, 11:29

Blimey Richard - more expense but I do like the car even though over the last 12 months I've spent £1,600 on electronic faults associated with the EGR valve - methinks I can c/o the wheel bearings - will remove the DPF filter and clean (any thoughts on that) - clutch under £500 say - Turbo will check it's play, I have the new type inline Banjo filter - will remove sump and check suction filter and flatten out indented drain recess, owt else yer can think of for that may be worth while on this semi stripdown - hopefully another couple of years out of it then get rid ...joe

PS ...Would it be worth while preventing the operation of the EGR valve, remove it's electrical plug and remap the Engine ECU to prevent carbon build up

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Joined: 09 Feb 2014, 08:42

Re: C4P Rocker Cover Crankcase RV

Post by nilrem » 12 May 2018, 02:57

I've just found a darn good write up of how the Rocker Cover PCV works - it was written by PUGPAINZ on peugeotforums.com on 19-07-14

Hi anyone interested!

Having searched all over the internet for advice and not finding much, now I have solved my issue I thought I would share it as it may help someone out there!

My problem was a blue smoke very smokey 307 1.6 hdi with excessive oil consumption. Smokey on first start up when cold which would clear a bit but blue smoke on power or when engine under load.

As expected, I first suspected the usual expensive suspects, valve seals, rings, turbo etc, and heard my wallet groaning. However on inspection I found excessive oil in the air intake pipe ( From mass air flow sensor to turbo),excessive oil at the cam cover PCV outlet, excessive oil at the turbo intake, oil in the intercooler and inlet and outlet pipes of said intercooler.

While it should be expected to see some light oil film from the crankcase breather system, whatever a peugeot dealer, mechanic, tech guy or your mate down the pub tells you, if you can dip your finger in dribbling oil in any of these areas in ain't normal!! Any more than a light film is too much.

What I discovered was that engine oil was passing directly out of the cam cover ( cover with the oil filler cap) via the PCV valve ( Breather opposite end of the cover from the filler) into the air intake system.

Almost another panic (as the PCV is integral to the cam cover and costS £100 ish) until i worked out how the PCV valve worked on this car. (postive crankcase ventillation) Breather system in plain english.

The PCV diaphragm is held in the closeD position via vacuum created in the air intake pipe via the small white branch connector attached to the intake and pushed into the cam cover. This diaphragm is held against a light spring pressure and is overcome by a crankcase pressure when need to vent out crankcase gases. The whole cover is designed to be an oil separator, allowing oil to return to the sump and vapour/gases to to be vented into the intake.

So to the issue..if there is not sufficient vacuum to hold the PCV diaphragm in the closed position, it will be constantly open and not doing its job, allowing excessive oily air to escape at its leisure from the breather into the air intake system.

The main thing (apart from the diaphragm) that maintains this vacuum is the O- ring on the air intake connector to the cam cover. What a pants design this is!! a nice pipe with two decent jubilee clips like most other engines would be better!

The replacement of the few pence o-ring to re-establish a good seal and get the PCV working properly solved this excessive oil burning problem!!
Of course I also cleaned out the inter cooler and all pipework affected.

Sorted my problem anyway, hope this helps someone, worth checking this little thing before a garage embarks on a process of elimination that costs you a fortune!
Good eh