2007 D5 (185)....Excessive Oil Consumption & Soot Filter Ful

[Mistero]

Mine's fixed!!!

A massive thank you to borys76 for his May25th post. Fitting part number 8642424 (Crankcase Breather Valve) has cured my car's problems.... well hopefully, (the improvement is astonishing - my MPG is climbing steadily, I have revs, I have torque, I can overtake!)

Originally, I thought I had turbo or EGR problems and I continued to drive the car cautiously to prevent it stuttering but a few months ago it was clear that something was seriously wrong when I couldn't climb hills at more than 30mph). Car went to P&R in Leeds and they diagnosed a blocked DPF - the dpf back pressure was 42 something or other when it should be less than 5. Car was drinking oil (but not as much as some others on this thread). A new quality after market dpf (not cheapest) was fitted because the original one was uncleanable - it was clogged with so much condensed oil vapours and 100k miles of soot. I drove that for a couple of months - the car was almost back to normal but didn't feel quite right. It didn't have top end power and torque seemed reduced.

At this point I think it's worth mentioning mine's a manual and therefore the revs drop between gears but if the engine stuttering started when I changed up I could hear a wastegate type noise from the front of the car. A neighbour and I traced this noise to the vent in the bottom of the air filter box. So the DPF being blocked basically backs up all the combustion process all the way back to the air filter housing! If your's starts stuttering, pop the bonnet and get someone to rev the engine to over 3k rpm to generate the wastegate noise. Look for a small rectangular flap on the right hand side.

After a month or so with the new DPF, the Low Oil message appeared again, so it was obvious oil was continuing making its way into the combustion process and probably not completely clogging the dpf like it did before because there's no soot build up there yet.

Reading this thread again, I thought it worth investigating the replacement of part number 8642424 (Crankcase Breather Valve) which looked like something I could tackle. It's a bit fiddly, a bit limited for space, but it's do-able. You'll need a T27 star driver and you'll need to loosen the mounting brackets for the 2 metal pipes running across the front of the engine block. The rest of it is fairly straight forward but I'm more than happy to detail the steps involved in changing the part if anyone requires it. The part cost £24.11 from FRF Swansea incl postage and VAT.

Essentially, the part contains a rubber membrane mounted on a spring which sits under the lid of the crankcase breather box, (the thing immediately to the right of the oil filter housing on the front of the engine). The membrane on the old part had become crinkly / rippled. The new part has a uniform shape to the membrane. I'm guessing that the spring becomes weak or the membrance becomes porous over time.

Anyway, now I've covered a few miles and been on some longer runs the car has it's old performance back, (it didn't immediately). I'm really happy and fairly sure it's fixed.

Which brings me to my final point. While I had the top off the crankcase breather box I noticed the oil separator cartridge sitting in the crankcase breather housing. It has a part numbers "PA 6 GF 30" & "39 310 50 998" stamped into it. (Google image 'Volvo 3931050998' for a photo.) It's a filter of some description and I want to change this part too but FRF's parts guy says it's not available separately - I have to buy the whole crankcase breather and oil filter housing assembly.

Does anyone on here know different? Is it available from somewhere? Or it the existing part cleanable with something that won't affect the engine oil?

Grateful for any guidance provided on this last point, please correct me if I've stated anything incorrectly, and, once again, thanks Borys76.

[Mistero]

Ah, and it was all going so well. For about a month, I thought mine was fixed and then one morning from cold under acceleration I felt the performance drop and it never returned, plus the MPG started dropping and after about 3 weeks the Low Oil Level warning message flashed up, confirming the new part had failed.

The good news is that I think I've proved the means by which the oil / oil vapours are contaminating the combustion process - I just need to find out why the part failed.

To this end, I've gone a bit further and replaced the whole breather / oil filter assembly, (part no 30677920) essentially to ensure the passageways between the housing and the block are not clogged and to replace the breather / separator cartridge. Cost was £124.20 from a main dealer and it took me about 2.5 hours to fit.

If you're thinking of tackling this, (and there must be a fair few of you out there with the same / similar problems, judging by the 500 views on this thread since my last post), then my top tips are:
- remove the right hand bend pipe between the egr and intake manifold - the housing will come out via that gap.
- make sure you can get to the 4th bolt between the 2 halves of the housing fairly early on - you may need a deep socket or small socket extension
- loosen / remove the top of the oil filter while it's attached to the block so it makes the housing smaller and easier to remove via the available gaps.
- put rags over the starter motor to stop oil falling on it when you remove the housing.

Once swapped, I checked the removed units - findings were (see photos):
- there were no oil sludge blockages in the passageways between the housing and the engine block.
- the oil separator valve cap had oil significant platters on the rubber diaphragm (but would this stop it working?).
- the oil separator cartridge was well and truly blocked - I tried forcing air into it from the bottom and the top.
- I've looked at all the parts and frustratingly, I can't work out the air flow and the action of the diaphragm / spring so if anyone knows, PLEASE tell me!

So that's the latest on my situation. I'll keep you advised on whether this works or not. Initial experiences on short journeys yesterday and this morning are good.

If anyone has tried the fix using part 8642424, have you had it fail the same as me?

David

[jamie1131]

I hope you have had wasted your cash. I ran the breather to a catch tank and blanked off the inlet manifold. There was no carry over at all. It was the piston rings that were knackered on mine.

[Mistero]

Thanks Jamie, yes, I'm hoping that too tbh.
I went for the spend on this 2nd part because of the performance was so improved when I fitted the breather valve part the first time round. I reckoned a) £125 might fix it because I get a new valve and that separator cartridge thing with it and b) I could tackle it so it was worth a punt.

[jamie1131]

Sorry, that was supposed to say I hope you haven’t wasted your money.

[SwissXC90]

Originally Posted by Mistero

I went for the spend on this 2nd part because of the performance was so improved when I fitted the breather valve part the first time round. I reckoned a) £125 might fix it because I get a new valve and that separator cartridge thing with it and b) I could tackle it so it was worth a punt.

The big question is: why did the breather valve get clogged up?

Through normal oil blow-by and simply many years / many kms of driving?
If so, OK.

Or at relatively low kms / few years of driving? In which case, where is the oil coming from? Is it excessive blow-by caused by worn pistons, or oil leakage from the turbo, or from somewhere else?

[Mistero]

Originally Posted by SwissXC90

The big question is: why did the breather valve get clogged up?

Through normal oil blow-by and simply many years / many kms of driving?
If so, OK.

Or at relatively low kms / few years of driving? In which case, where is the oil coming from? Is it excessive blow-by caused by worn pistons, or oil leakage from the turbo, or from somewhere else?

Thanks Swiss, I compared the breather valve caps (the original one and the second one) when I took the photo. On the one which had done 100k miles the spring and the diaphragm are very stiff. On the second one there's only oil splatters on it but it looked normal with no holes.

What I'm hoping is that the fault lies with the blocked oil separator cartridge. I can't suss out the vapour flow through the thing (I think the gasses might operate under vacuum and the oil, once separated, drains under gravity) but it kind of makes sense that once pressure builds due to a blockage of oily residues it prevents the diaphragm / spring in the cap from operating. I don't know - it's just a hunch. I wish I'd done the pump test on the new cartridge but it's fitted now.

Like others have stated on this thread, it could be the turbo or the piston rings but I've spent my money believing 30677920 is worth a punt, I've fitted the new housing and I'll report over coming weeks how the oil usage is, performance/ mpg is and whether any stuttering has returned.

[Nickthecook]

I've have a theory, one that as yet remains unproven. But first the background. I too have the same problem of DPF issues and excessive oil consumption. The oil is without doubt being burned off through the CCV system. The point made earlier about exhaust temps is one that certainly interests me. I think we are all suffering from exhaust back pressure as a result of blocked DPF's. I shall certainly be monitoring mine from now on. I have noticed my oil temps running high, about 10°C-15°C above coolant. Ive also noticed at low revs and during easy acceleration, the DPF pressure is Ok. However, give it some beans and there is just far too much restriction to allow the gasses to escape freely. Pressure spikes and a regen is kicked off. I've monitored my DPF temperatures as recently as last Saturday and was seeing a peak of 680°C. Not for long on these Welsh roads, but still an acceptable temperature for regeneration to take place. However, I'm now wondering how far back this heat may be travelling due to its restricted passage to the outside. Incidently, the CAT temp was roughly half that of the DPF, still 300°C+. I'm sure this is undoubtedly having an effect on oil temperatures and the level of burn off. As for carbon deposits on oil rings? it's highly plausible, but with such a high amount of bore wash constantly passing the rings, the jury's out on this one.

My recent DPF woes left me driving around in restricted Power mode for a few weeks, this happens when the Soot warning remains uncleared for 'X' amount of starts. At this point I took the DPF off and backflushed it with a pressure washer. (Needed the car for work) It was now down to a more acceptable level of restriction. I should point out that during these few weeks, I hardly used a drop of oil. If the problem was Valve Stem Seals or Worn Rings, oil consumption would only have dropped slightly with thre reduced power setting. It didn't, it virtually stopped drinking oil all together. Why? For Reduced Power mode, the ECM limits the flow of fuel through the injectors. The Revs are not restricted, however the EGR fully closes and the throttle body is fixed in a set position. Strangely, you do still get boost, although with limited fuel it's still slow going. 60mph-70mph is still achievable, it just takes a lot longer to get there. Obviously the Regeneration program is disabled during this period. This reduced power mode is however far less restrictive than a blocked DPF. That will bring you to a stand still on the slightest of inclines. So from my experiences so far, I can safely say regenerations make a huge difference to my oil consumption. Probably as a result of heat, oil dilution and excessive back preasire.

I've recently purchased VIDA and knowing the current DPF will probably end up on the scrap heap, I've been having a play. Firstly I reset the pressure sensor values to get it out of reduced power mode. I then tricked the car into thinking it had a New/Clean DPF by resetting the counters. The car is running beautifully, however it drops into regen at least once per day. This is as a result of the sensor picking up massive spikes under acceleration. It goes to show that there can be problems long before the driver feels any change in the vehicles drivability. I would imagine the DPF is now clogged with ASH, possibly Plugged Ash Deposits aswell. At Tickover and with a very light right foot, its fine. However, at a certain flow rate restriction builds quickly.

To compound matters, Volvo advise 0w-30 A5/B5 oil, which is NOT Low SAPS. After as little as 33,00 miles 50% of the filters capacity can be taken up with ASH. This mostly comes from engine oil wear additives and A5/B5 produces nearly 50% more ASH than a Mid SAPS Oil like a C2 or C3. ASH cannot be burned off in a regeneration, only soot can. All of the affected cars have coverd a significant mileage, mine currently stands at 227k. I put an after market DPF on it about 18 months ago, but stupidly I didn't get the ECM work done at the time. Therefore, although It was clean and clear, the ECM thought otherwise. Because of This, I can't really draw many conclusions, other than it lasted about 10 months. Up until the point when the Soot filter warning came on, it was consuming oil at the rate of about 1ltr every 1,500 miles, it was however regenerating far too often. Was this due to pressure drops or inflated counters? I'm afraid I don't know.

Here comes the theory. As well as the problems listed above, I also have a vacuum leak on my brake servo and for what ever reason, during regeneration the pump is drawing in air through a significant leak, somewhere. I thought it was the EGR cooler bypass valve (only fitted to
Manual cars) However, Volvos New Car Fact Sheet for the Euro4, only shows this valve being utilized at warm up. Maybe they forgot to mention it opens for regens too or.maube it doesn't, maybe the servo leak gets worse with the heat or maybe its coming from somewhere else entirely. I do know where it goes though. Straight into the head of the engine to be dealt with through the Crank Case Ventilation System. I've found evidence online of this problem affecting other diesel engines and causing oil to be burned as a result.of a significant jump in crank case pressure.. In one case there was what looked like a copy of a service manual for a Defender, it states clearly that an uncontrolled vacuum leak can cause the engine to burn oil due to the associated increased crank case pressure. I also found write ups on diesel forums from Owners who had blue smoke and a badly leaking vacuum line. They clamped off the line above the leak and with in minutes, the exhaust clears. I might also add that the pump is driven off the exhaust cam (same side as the cam cover CCV pipe) and might well be spraying oil directly at the breather uptake, aswell as adding to the pressure.

MY PLAN IS;

Monitor with Torque Pro to ensure the engine is never turned off during post injection. Can be seen through commanded EGR values. On the app, set 94.9% EGR = Regeneration in progress.
Fix all vacuum leaks.
Replace the ASH filled DPF
Replace the Pressure sensor, if the differential reading doesnt improve with new DPF.
Replace one way breather valve.
Clean entire breather system*
Use 0w-30 C2 or C3 instead of A5/B5 and change more frequently.
Use VIDA to determine speeds and time needed to achieve a decent regeneration. *
Monitor exhaust temperatures, frequency of regeneration amd oil consumption.

* The first time that breather pipe came off was when I replaced the lifters shorty after purchase. On that occassion it was full off oil.

* (In regeneration for 12miles on Saturday on National Speed limit A roads. Only tipped 600°C Five times and the total time spent over this temperature was about 90 seconds.) Braking for traffic is your DPF's enemy.

[Nickthecook]

Before you dismiss the Vacuum pumo therory. At full acceleration, say 3,500rpm, the pump will be dumping 5x the quantity of air into the CCV as it does at idle. This air is.goung.to be hot too. (leaky mounts dont count, the supply.is shut.off at 1,100 rpm) Have you ever touched a 12v compressor when it's been running for a while? Gets hot, doesn't it? The previous owner had to put a new vacuum pump on the car. I wonder if the oil is also getting burned inside the pump due to extreme heat?

[Mistero]

Two very interesting posts, Nickthecook, I read both with interest.

Changing the whole crankcase breather housing hasn't cured my car's problems but it has improved them. If I accelerate hard-ish from cold the DPF gets clogged quite quickly and the car stutters. If I leave it idling for 30 -40 secs before I pull away when cold it doesn't stutter. Driving once rolling is much improved too, with less stuttering. And the low oil warning hasn't come on, but I can feel the power is down on what it should be.
I still think it was worth doing what I did to replace the breather valve and that breather filter cartridge thing. It may have cost £150 but I did it myself and it was worth a punt.

Are you getting an uneven rough fire on a cold start, too?

I'm watching this thread with interest for any progress or suggestions you make.

David