pcv question

[dave_mito]

is it normal for the hose that runs from thee top of the tank back into the block, to run boost pressure
or have I put a 1 way vavle on wrong. cleaned the system and replace a pipe a week or 2 ago and now its split


thanks in advance

[M-R-P]

It should draw some pressure from the inlet manifold but only a little.

One way valve? there isn't a one way valve on the PCV afaik.

[Harvey]

Here's a parts list what bit are you saying ?.

http://i1168.photobucket.com/albums/r499/harveysr/imagejpg1_zps3ba8bbc0.jpg (http://s1168.photobucket.com/user/harveysr/media/imagejpg1_zps3ba8bbc0.jpg.html)

[dave_mito]

Number 2 seems to be getting manifold pressure.
has a slight split in it

[LeeT5]

It should draw some pressure from the inlet manifold but only a little.

One way valve? there isn't a one way valve on the PCV afaik.

No 11 is infact a 'one way valve' banjo bolt. However, when fitting these to the car you most only fit the new banjo bolt to the left side, ie, PCV hose to the underside of the manifold (nearest the timing cover).
Do not fit No 11 (dealer supplied) to the right side. You must reuse the hollow screw that you removed. So, clean it up and refit with two new copper washers.

I'll be totally honest with you Dave. I have now replaced two PCV systems on both my P1 R and P2 R and I can't understand why you 'cleaned' the PCV system? It shouldn't really be cleaned as the pipes and hoses become clogged and go hard and brittle over time. You should have replaced the entire PCV system. Just cleaning it is a total waste of time. The jobs a complete PITA anyway.....Just replace it!

[dave_mito]

I replaced number 1 and number 6.

can the one way banjos wear over time

[LeeT5]

I replaced number 1 and number 6.

You needed to replace No 8!!! It's the most important part of the PCV and the part that causes the most issues! Infact, you could have got away with not replacing No 1 as they only fill with crud by about 10-20%. All the rubber hoses should be replaced as they become hard and brittle over time.

In replacing No 8, you'll also need No 11 - but follow instructions as per post #5.

I went out to a XC90 petrol last week and No 6 had completely snapped in half!

I'm afraid if you've put the car back together again and only replaced 1 and 6 then AFAIK you've wasted your time. I would do it again and this time, replace items 8, 2, 4, 11 and 10 (x4) also.

I hope you also replaced the inlet manifold gasket as well as an oil change?

[LeeT5]

Can the one way banjos wear over time?

They don't wear, they just get blocked up with carbon.

You just replace them mate! accept the right side. This must remain a hollow screw.

[LeeT5]

If you just ask your local Volvo parts dept' for a 'PCV kit' they will supply you everything that you need to do the job.....properly! :wink:

[dave_mito]

Most of number 8 is a metal pipe. All the rubber hoses were still veey rubbeey, so perhaps changed at some point. I pressure tested them and flused them out.

[M-R-P]

That's what I did with mine - flushed everything (there was very little crud in any of the PCV pipes), cleaned the left banjo (didn't realise there was one on the right) and put it all back together. I didn't remove the inlet manifold to do the job so that saved me some time and money.

[LeeT5]

Most of number 8 is a metal pipe. All the rubber hoses were still veey rubbeey, so perhaps changed at some point. I pressure tested them and flused them out.

I'm sorry buddy, but the small plastic tube is only about 4mm ID. The carbon build up in that pipe is impossible to clean out. Just because you flushed it through, you will not know if you've actually cleaned out all the carbon deposits. You may have had liquid flow through the pipe but due to the length of it, for all you know, you may have just dislodged some of the build up of crap internally. You cannot see through the pipe to know it is absolutely clean!! Now you've fitted the pipe, some of the dislodged carbon may have blocked the one way valve on the manifold.

The only way you can be absolutely sure that the PCV pipe is totally clear of contaminated carbon deposits is to replace the whole pipe. Otherwise it will always be a big fat ? as to wether or not its clear and the PCV system can breath as it's designed to.

Cleaning the PCV pipe is NOT recommended. It should be replaced only.