PCV Write-up for 1999+ Volvo 5-cylinder 31325709

[mikealder]

Get the PCV done, when you have the catch tank off the front of the engine connect a 5/8" hose to the lower port in the engine block where the PCV tank connects, secure it with a Jubilee clamp and try and blow through it, if you can't blow through it the oil return path is blocked and you need to get the crud out of the PCV drain port which is a cast channel within the engine block that continues down through the sump before turning through 180 degrees, mine was blocked right at the end of the pipe which wasn't possible to clear out without dropping the sump.

Here is a write up with pictures of what I did to the V70 phase one, slightly later engine than yours but look at the internal pictures of the sump later in the write up which shows where it can block, note any prices quoted are for the parts from the Volvo main dealer bu tthey are in UK Pounds.

This is a quick set of pictures showing how to get to the PCV on the V70/ early S80 with the Denso engine management system without a Turbo, the engine should appear thus:



Start by taking the cover off to gain acces to the coil packs as you will need to remove the top hose from the PCV system later on, at the same time remove the plastic cover from the fuel rail:



Take off the inlet pipe running between the mass airflow sensor and the electronic throttle motor, there are a couple of other pipes connected to this that need disconnecting and an electrical connector but the pipe should come away leaving the engine looking like this:



Next to come off is the Electronic Throttle Motor, four 10MM headed bolts will release it from the inlet manifold but the cable is trapped between the starter motor and the engine block so secure it somewhere safe within the engine bay, take the oppertunity to clean it out on both sides of the butterfly valve with carb cleaner while it is away from the engine



Disconnect the wiring from the injectors and put the loom out of the way, no need to number the plugs as it is obvious what goes where assuming the conduit is still in one piece:



Disconnect all the Vacuum lines from the inlet manifold:



Put some cloth or kitchen roll around the valve on the end of the fuel rail and depress the valve in the center of the schrader valve, fuel will escape but you need to depressurise the fuel system before taking the injector rail to bits, once no more fuel is escaping throw the fuel soaked rag in the bin:



Remove the two 10MM head bolts securing the fuel rail to the inlet manifold and the pull the fuel rail complete with the injectors away from the engine, take care at this point as the fuel delivery pipe is still attached to the fuel rail:



Invert the fuel rail to reveal the three Torx head screws securing the clamp plate which locks the fuel injectors and fuel delivery pipe to the fuel rail:



Remove two of three screws and release the third screw to let the clamp plate slide out to the side, try not to knock any of the injectors at this point, once the securing clamp plate is clear of the fuel delivery pipe simply pull the pipe from the fuel rail:



With the fuel rail disconnected from the delivery pipe remove it from the engine bay and put it somewhere safe, as a tip slide the clamp plate back in to place and put the two Torx head screws back in to avoid the injectors falling out, this also keeps the two screws safe from getting lost:



Next is the black plastic injector vapour purge pipe, this simply pulls away from the inlet manifold, again put it somewhere safe:



Follow the dipstick tube down to where there is a bracket attached to the underside of the inlet manifold, you need to release this, the bolt is 12MM head, once this is off the car feel further aft towards the engine under the inlet manifold to locate another 12MM head bolt between a bracket that connects between the engine and inlet manifold, remove the bolt between the bracket and the inlet manifold:



Next remove the top PCV vent hose from the top of the engine, if it has a crimp type clip attaching it to the head use a screwdriver to lever the clip to release the pipe, the clip will be scrap and is best replaced with a suitably sized Jubilee clip on reassembly:



Remove all the upper bolts securing the inlet manifold to the engine block, the three lower nuts only need to be released as the inlet manifold is notched to aid removal, with a 6" wobble extension it is possible to release the inlet manifold bolt near the thermostat even if it is difficult to see the nut!



To release the lower bolt on the right side of the inlet manifold it is easier to use a 10MM spanner as there is no access for the ratchet:



To get the inlet manifold off simply lift it up to clear the lower stubs then push the PCV top hose through the pipes and the fuel rail through the inlet feed pipes, put it to one side as you now have access to the PCV, time taken to get to this point is around 30 minutes.



Remove the bracket that connects between the inlet manifold and the engine block as one of the bolts securing the PCV tank to the block is hidden behind it:



With the bracket out of the way remove the two bolts securing the PCV tank to the front wall of the engine block, even the second bolt is fairly well hidden:



Sorry for the state of these next few pictures but I was using a phone with hands soaked in oil by now! with the PCV tank pulled away from the engine you can get at the coupling between the lower engine port and PCV tank, this is where the oil drains back to the sump from the PCV and is often the port that is most blocked/ sludged up:



The small silver coupling piece simply pulls from the engine block to reveal the port (and sludge):



At this point attach a 5/8" internal diameter hose to the lower PCV tank port in the engine and try to blow through it, if you can blow through it and hear bubbling from the sump the port isn't blocked, if you can't blow through the port it is blocked and needs to be cleared out to address the PCV issue:



I decided to send a length of clear plastic pipe down the lower PCV port to try and unblock it, the sludge and carbon built up inside the pipe which was reduced in length cutting off the now blocked section of pipe before repeating numerious times until no further sludge could be removed, not ideal and if it is this bad consider an oil change before starting the engine as some of the crud might have dropped in to the engine sump. In my case the PCV port was still blocked and I couldn't blow through the 5/8" hose (more on this later in the write up)



The blow-by pipe from the PCV tank to the inlet manifold is heated by the engines coolant system, it is possible to take this to bits without disturbing the coolant system and clean out the pipes, to do this strip off the innsulation and take the pipe off the coolant pipe:



When you are sure the PCV drain is clear refit the metal/ rubber collar to the lower port:



Refit the tank and secure the hoses with Jubilee clips rather than the crappy Volvo crimp connects, the tank costs around £30 new and the two small connections to the engine block are around £3:50 each, a new pipe to the top of the head is close to £40, the PCV blow by pipe I cleaned out and re-used, adding innsulation when rebuilding.



When you refit the bracket to the engine that supports the inlet manifold leave it loose until you have attached the inlet manifold as this makes it far easier to connect the two items, once you have the bolt secured in to the underside of the inlet manifold secure the bracket fully to the engine



After that little lot the reassembly is really the reverse of taking it to bits, the first time I tried this took me around two and half hours the second time was around an hour excluding time taken to clear out the blocked ports on the engine.

In the end the sump had to be removed to clear out the oil return path as it was blocked with carbon, you can see where the PCV drains down through the square part of the casting then exits to the sump through a pipe that is close to 180 degrees bent upwards relative to the drain port, this 2" section of port is impossible to clean out without removal of the sump which is why the blowing down the 5/8" hose earlier in the write up is so important as sump removal is a real PITA:



- Mike

[matthew1]

Mike, outstanding. I'll add links to this in Links to Major Repairs (P80) and in its P2 counterpart.

Tip o' the hat to Justin for the head's up on this!

[98T5]

Very nice write up. I will be using this one next time I need this done. Paid the shop almost $800 to do it the first time. never again.

[kseyoum]

Thank you for the write-up.

I actually followed your procedure to service my '02 XC70 (turbo) PCV, but with this added caution:

There is a short hard plastic vacuum hose that goes from the top of the breather box to the underside of the manifold, close to the power steering pump that can break easily. You must loosen/remove this hose off the intake manifold before moving the manifold. It is in a very awkward location but requires a 17mm wrench to do it. Because the hard hose has an insulation, one can easily think that it is a flexible hose. Note that this hard hose has the coolant line connected to it.

Although the breather box and the bottom fitting had some carbon build-up, the long breather hose assembly was clean. As long as you don't break the hard plastic vacuum hose, you can re-use it (at least in my case).

Cheers, -Kef

[rTiGd2]

Today I am trying to muster the courage to do this myself (mostly because of cost but also because of your kind words, advice, and link to this post in my own question.)

So, other than the oil trap itself (surprisingly 'cheap' from the dealer) you mention a few other things that shall need replacing such a clips and commented about a connecting pipe. What clip sizes would I need to get, is this connecting pipe always required, or only in extreme cases of sludge inside it? Oh and finally, any ideas where to get a tube for blowing through the port into the engine (and what gauge is best?)

I know these are probably all very basic questions but I'm a computer guy who loves to tear things apart and fix them, certainly no mechanic or technician (but the joy of the authors of posts here, such as yourself, is that you can pretend to be one every now and then.)

Kindest regards, Tig.

[MMT51]

Mike

Great write-up. What type insulation did you use to re-wrap the long breather/coolant hose?
Thanks, Peter

[abscate]

Im sure just some pipe foam from a home store will work well.

The coolant warming of the PCV system on 1999+ cars, Im convinced, keeps this system much cleaner than earlier versions. I haven't cleaned mine yet, after 160k miles/16 years.

[mikealder]

Tig, If you get a PCV kit from Volvo it will contain everything you need including hoses and those clips that you tension with special pliers (Oetiker clamps - speeling probably wrong) I prefer to use Stainless Steel worm drive/ Jubilee clamps depending upon which side of the "pond" you live on. Best bet for the clamps is to take the pipes down to your local motor factors and get suitably sized clamps.

Main items you will need is:
Inlet manifold gasket £15
ETM gasket £3:50
PCV Tank £20
PCV Tank to top of engine hose £45
PCV Tank to blow-by gas port (short stubby 90 degree bend hose) £8
PCV Tank to oil drain port coupling £5

Above are all from Volvo costs are roughly what I paid last year from memory, I bought the two port connecting pipes as they were cheap, the ones that came off could have possibly been re-used but for the sake of less than £20 it's not worth prating about. The hose from the tank to the top of the engine is a tad costly but this one often breaks where it exits from under the engine top cover, a new pipe is more peace of mind knowing you won't have to rip out the inlet manifold to swap the pipe at a future point.

In addition you will need a can of carb cleaner (£5), some rags, about a meter of 5/8" internal diameter rubber hose (£5)(to blow the oil drain port through) and I used about three meters of 6MM diameter clear plastic hose (£6) to rod out the lower oil drain port, the dirt goes in to the hose as you push it down to the base of the sump, keep cutting off the blocked 6MM clear pipe and discard then repeat the rodding out until the port is clear, all these bits can be purchased from a local motor factors or even Halfords in the UK.

The only hose I didn't change on the PCV system is the main blow-by return pipe which is lagged and also carries coolant to heat the blow-by return pipe, when you separate the metal pipes under the insulation you can use carb cleaner to blow out any dirt within the pipe then re-attach it to the coolant pipe with tape, for insulation I used a wrap tape encompassing both metal pipes, there isn't enough clearance for the foam pipe insulation to sit under the inlet manifold. The prime reason for not changing the blow-by return pipe is down to cost, the pipe is bloody costly and being a metal pipe it is easy to clean out. Leave the coolant pipe in situ as there is no point in draining the coolant system down for carrying out this job - Mike

[rTiGd2]

Thank you Mike, that's exactly the shopping list I needed for tomorrow (let's hope it's a little less wet)

Halfords, oh dear.. Hadn't heard of Motor Factors before, thanks for that heads up (your side of the pond, Bristol )

[mikealder]

Motor factors is a generic term I use for small independent car accessory shops often found in most towns/ cities, often with more experienced owners that offer genuine advice than spotty youths in Hafrauds.
Another place to go for the generic non Volvo specific parts is Euro Car Parts they will have a number of retail units near you and they are decent price wise - Mike