Guide: replacing PCV/ oil seperator system
 

Following being aware of a highish oil consumption on my B4184S2 engine (154k miles on it) with oil appearing under the spark plug cover, and having no vacuum when lifting the oil filler cap with the engine running. I decided to investigate the PCV (positive crankcase ventilation)/ oil seperator system.

I did some research from the V70/850 forum and decieded to go for it and replace the oil trap and pipework that could be blocked. Spoke to my friendly volvo dealer who had never ordered these parts so I had to explain exactly what i needed. In the end and orderd some new parts which i mention further down the thread.

Tool wise I used;

Good 3/8" ratchet set
1/4" ratchet set
t-star bit set
extendable magnet for retreiving lost bolts
wire cutters
small and large screw drivers

I didn't take many photos i'm afraid, but the numbers in here should refer to the arrows in the PDF file attached which should help if unsure.


1. Disconnect and remove battery, little tab to flick up allows it to slide and be lifted. Not required but good for placing tools and gives more room.

2. Remove spark plug covers, 6No T-star screws

3. Remove fuel rail cover, 2No T-star screws

4. Remove throttle housing cover, 1No long T-star screw, then carefully remove the 2 black plastic screws to lift of cover.

5. Remove section of air inlet pipe from throttle housing towards air filter. 1No jubilee clip at each end. Just above the top jubille clip there is a 1” elbow coming off the main pipe disconnect the 1” tube after the elbow

6. Remove the 2No hex bolts holding down the fuel rail.

7. Disconnect the connector from each injector.

8. Using a small screwdriver disconnect the fuel line to the FPR (fuel pressure regulator) and carefully extract it

9. Remove the vacuum hose between the FPR and the inlet manifold, remove the tiny tube from the inlet manifold which goes to the air filter housing. Also remove the solid vacuum pipe from the inlet manifold.

10. Remove the fuel rail, very carefully lift up. Then put in a safe clean place out of harms way

11. Disconnect throttle cable and undo 3No 10mm hex bolts holding the bracket to the inlet manifold.

12. Remove the throttle housing removing the wiring connector as you lift it off. 4No 10mm hex bolts (optional but allows you to clean it and you have more room)

13. Remove the idle control valve, and disconnect the wiring connector. 2 No 10mm Hex bolts (optional but allows you to clean it)

14. Remove the top crankcase ventilation pipe from between the spark plugs. 1 small jubilee clip.

15. Disconnect the inlet manifold from the pump. Slacken one bolt and remove the other, 12mm

16. Remove the oil dipstick pipe. 1 small bolt near the top, then carefully pull out.

17. Undo the top bolt from the bracket which sits underneath the inlet manifold providing support, 1No 12mm hex bolt. Be careful not to get bits of crud into the dipstick hole, you could put it back in but there is more space if its not there. I worked from underneath with some long extensions to a 3/8” ratchet.

18. To improve access drain of 1 litre of coolant from the cooling system and remove the top radiator pipe from the thermostat housing, 1 jubille clip.

19. Remove the 5 bolts (I think there was 5?) from the holding the inlet manifold onto the block. The one by the thermostat housing is tricky to see.

20. Carefully pull away the inlet manifold, and lift upwards to your right slightly, it may catch on the throttle cable bracket and coolant hose but there should be enough space. As you remove it there is a rubber pipe on the left hand end which needs to slide off. The top crankcase ventilation pipe will need negotiating around the injector wiring and then through the inlet manifold. This can be done on your own, but easier with 2

21. You can now clearly see the PCV/ oil separator. Remove the hose clips holding the ‘mid’ pipe onto the block

22. Remove the 2 bolts securing to the engine, one is easily visible. The other is not, my 3/8” drive 10mm socket would not fit in the gap so you’ll need a ¼” drive set for this.

23. If your lucky the PCV will then just pull away, if not it will be held on by a very tricky t-star jubilee sort of clip on the bottom breather pipe.

24. Look very carefully at the lower orifice, mine I think was blocked up. I completely removed the pipe and carefully got out all the muck. I used a small pipette, I know I pushed some into the engine but I was happy that I’d cleared the passage. I did an oil change after a few runs making sure all was ok with the work I’d done.

25. Carefully re-build in reverse order. I replaced the following parts;
8642185 Oil separator, needed one new hose clip on the middle pipe
9497534 Top crankcase ventilation hose (need 2 new jubille clips)
9458503 Intake manifold gasket, cleaning both faces before putting back
30713614 x4 (2 O rings per injector)
new gaskets for idle control valve and throttle housing

The only tricky bit when re-building seems to be getting the 2nd bolt on the oil seperator and the drivers side bolt on the intake manifold due to the angle the bolt needs to go in at.

26. Once complete and happy all is ok restart and check you now have a vacuum!

The only other tip I found was to allow a full day for this if you've never done anything like it. All in (minus the oil change) took me about 7 hours, but I had never done a job this complex before!

Phil

Great guide. Thanks for taking the time to do it.

Since you recomend dropping 1 litre of coolant to remove the top radiator pipe, would it not be worth doing this when doing a full service ie, coolant change, spark plug change etc.

I really need to do this!! Thanks for the guide!

since doing this has it made a difference to the oil consumption and driveability of the car good write up

I'm not sure i would do this with a general service as it takes best part of a day to do, but its a job I would do again if I thought my car needed it doing. Although if your changing the starter motor/ have the inlet manifold off for anyother reason you had may as well do it!


Phil

Hi Phil and anyone else who has done this.

What was your oil consumption before and after replacing the PCV as above?

Where were your high oil consumption symptoms if any? Black soot collecting on the exhaust pipe tip?

When you removed the dip stick, was oily smoke coming out ie a symptom of a blocked PCV?

thanks

Im finally gonna do this!

Thing is I have the B4194T engine.

I was just windering if these parts numbers still suit.... or are the parts different for my engine? If so, does anyone know what I need for the P1 T4 engine?

8642185 Oil separator, needed one new hose clip on the middle pipe
9497534 Top crankcase ventilation hose (need 2 new jubille clips)
9458503 Intake manifold gasket, cleaning both faces before putting back
30713614 x4 (2 O rings per injector)
new gaskets for idle control valve and throttle housing

Many Thanks guys!

I can't say i monitored the oil consumption before i did the work but i was putting oil in on regular occasions. Since doing the PCV job i do still have to top up but nothing like before, i am still getting a bit of oil leaking around the filler cap but i didn't replace this seal. There was no smoke out the dipstick tube but there was pressure, i.e. pushing out. Where as now there is a vacuum i.e. sucking in

I havn't got a copy of vadis on my laptop, hopefully someone who does will be able to advise on what the t4 engine needs.


Phil

PCV rpl
 

How many labor hrs does this job call for?!

Great overview, finally a solution for my wife's car. is there anyone who could send me the PDF file? the link does not seem to work anymore..