D5 (2005 on) Possible cause of DPF Issues with High Oil Consumption.

[Nickthecook]

Many have either sold or scrapped their Euro4 D5 after hitting a dead end in trying to resolve this problem. Firstly, if you're using the recommended 0w-30 A5/B5 and you're burning oil, theres a good chance your CAT is poisoned with Phosphors. This engine oil is not CAT and DPF friendly. But frst we need to understand why the Engine is consuming so much oil. I've read 100's of posts on various sites about D5 DPF's getting repeatedly blocked and the oil consumption as a result of almost continuous regenerations. Regenerations that never actually seem to clear the DPF. Many believe, because they've been told, that the oil burning is as a result of engine damage from bore wash. Bore wash can occur when a regeneration is interupted and diesel left in the cylinders can wash down the side of the pistons into the sump. They hypothesize that this causes wear and that gases are now blowing by the pistons, creating excessive crankcase pressure that forces oil through the breather into the induction system. This oil produces high levels of ash, due to the level of SAPS contained in it. Odd how every bit if information out there regarding OIL, CATs and DPF's, states that only a C grade should be used, as other grades will irreversibly damage the Catalyst and block the DPF and reduce it's lifespan. Ash can't be burned off like soot, it can only be physically cleared out. I agree in part with this, in that it is excessive crank case pressure that is responsible for the oil consumption. I don't however think it's being caused from blow by, at least not in all cases. After all, blow by isn't selective about when it choses to happen. This high oil consumption only occurs during regenerations and increases inline with the frequency of them. So what's different about a regeneration that could cause excessive crank case pressure? On the D5's fitted with the M66 box, is an EGR Cooler Bypass Valve. This valve is only in operation during engine warm up and Active Regenerations. It's purpose is to allow uncooled EGR gases back into the system to reduce engine warm up times and to help lift the exhaust gas temperatures during a regen. This valve is electronically controlled, but is physically opened by a Vacuum Actuator. (Volvo calls it a Vacuum Box) If this actuator is leaking badly and the valve fails to open, a) more soot produced as a result of slower engine warm up. b) an integral part of the regeneration process won't be working and as a result regeneration gases won't get as hot. c.) You won't get any warning or code as the actuator isn't monitored by the ECM. d) This is the bit that I 'THINK' is causing the oil problem. The Vacuum pump is going flat out trying to pull a Vacuum on the leaking actuator and the Vacuum pump vents Into the top of the Engine to be fed through the breather system. I've searched many diesel forums and discovered that Vacuum Pumps that vent this way can lift crank case pressures sufficiently for the car to start burning oil. One guys exhaust stopped smoking within a minute or so of him clamping a leaking vacuum hose. When I replaced the lifters on mine, the metal breather pipe that runs over the top of the rocker cover, was full of oil. My D5 has covered 226k, it ticks over 1rpm or 2 rpm either side of 700rpm. It certainly isnt lacking any power and at idle there is absolutely no sign that I have blow by or excess gas/pressure. When the engine is cold or in regeneration, there is however the tell tale glug,glug,glug noise from the oil filler. A sure sign of a vacuum leak. Some of you may have noticed this noise when you've had a leaking engine mount. Imagine it at 2,200rpm with the oil filler cap on. I may be barking up the wrong tree, but there doesn't seem to be any inbetween. There's Euro4's that don't use a drop of oil and those that drink it by the bucket. I'm going to clamp off the line to the EGR Cooler Bypass valve and monitor the oil consumption. I'm also going to look into whether the engine could run on a C grade oil, with more frequent changes. If you're currently having similar problems with a Euro4, or have experienced them in the past, I'd love to hear your comments. I know it seems like a long shot, but logically it is possible. I will certainly know either way within a couple of weeks.

[skyship007]

First of all I would not use any 0w30 oil in a diesel that is out of warranty.

The reason an 0w30 is recommended relates to fuel economy and once a diesel has run in and out of warranty, it's a far better idea to use an 0 or 5w40 oil. The only type of small car diesel that should use an 0w30 oil is the hybrid diesel. The rest of the engines have lower oil consumption figures with an Xw40.
If you do 2 oil changes per year then it makes sense to use an 0w30 in winter and a 15w40 in summer.

Both the Acea C and E cats are rather lacking in anti wear terms in comparison with A3/B4 oils recommended for the non DPF afflicted engines. One way of correcting that is to use half a can of Liqui Moly Ceratec oil additive every oil change interval. It contains both Moly (Mo) and Boron Nitride additives to reduce main block wear and it also helps reduce the oil consumption by filling in any pitting.

I would also reduce the oil change interval to 5 or 6000 miles max, as DPF's contaminate the oil with diesel and the bio fraction does not evapourate off, so that results in it thinning the oil. Diesel contamination also interferes with the function of the anti wear additives, although it does not effect the way Ceratec works.

Short tripping is not good for a DPF, so think about fitting a sump or even block heater. The sump heat pads are cheap and easy to fit, but not as effective as a real block heater. The cost of the electricity is about the same as the fuel saved, but they are good news in engine wear terms during the winter in particular.

Finally, make sure the CCV is not blocked up if you have been doing long oil change intervals, as that will result in a higher oil consumption.

Obviously if a diesel is smoking at hot idle, try and find out why. Most likely reasons are gummed up injectors, leaking HG or hose leaks (Brake system or turbo).

[Scooser]

Originally Posted by Nickthecook

Many have either sold or scrapped their Euro4 D5 after hitting a dead end in trying to resolve this problem. Firstly, if you're using the recommended 0w-30 A5/B5 and you're burning oil, theres a good chance your CAT is poisoned with Phosphors. This engine oil is not CAT and DPF friendly. But frst we need to understand why the Engine is consuming so much oil. I've read 100's of posts on various sites about D5 DPF's getting repeatedly blocked and the oil consumption as a result of almost continuous regenerations. Regenerations that never actually seem to clear the DPF. Many believe, because they've been told, that the oil burning is as a result of engine damage from bore wash. Bore wash can occur when a regeneration is interupted and diesel left in the cylinders can wash down the side of the pistons into the sump. They hypothesize that this causes wear and that gases are now blowing by the pistons, creating excessive crankcase pressure that forces oil through the breather into the induction system. This oil produces high levels of ash, due to the level of SAPS contained in it. Odd how every bit if information out there regarding OIL, CATs and DPF's, states that only a C grade should be used, as other grades will irreversibly damage the Catalyst and block the DPF and reduce it's lifespan. Ash can't be burned off like soot, it can only be physically cleared out. I agree in part with this, in that it is excessive crank case pressure that is responsible for the oil consumption. I don't however think it's being caused from blow by, at least not in all cases. After all, blow by isn't selective about when it choses to happen. This high oil consumption only occurs during regenerations and increases inline with the frequency of them. So what's different about a regeneration that could cause excessive crank case pressure? On the D5's fitted with the M66 box, is an EGR Cooler Bypass Valve. This valve is only in operation during engine warm up and Active Regenerations. It's purpose is to allow uncooled EGR gases back into the system to reduce engine warm up times and to help lift the exhaust gas temperatures during a regen. This valve is electronically controlled, but is physically opened by a Vacuum Actuator. (Volvo calls it a Vacuum Box) If this actuator is leaking badly and the valve fails to open, a) more soot produced as a result of slower engine warm up. b) an integral part of the regeneration process won't be working and as a result regeneration gases won't get as hot. c.) You won't get any warning or code as the actuator isn't monitored by the ECM. d) This is the bit that I 'THINK' is causing the oil problem. The Vacuum pump is going flat out trying to pull a Vacuum on the leaking actuator and the Vacuum pump vents Into the top of the Engine to be fed through the breather system. I've searched many diesel forums and discovered that Vacuum Pumps that vent this way can lift crank case pressures sufficiently for the car to start burning oil. One guys exhaust stopped smoking within a minute or so of him clamping a leaking vacuum hose. When I replaced the lifters on mine, the metal breather pipe that runs over the top of the rocker cover, was full of oil. My D5 has covered 226k, it ticks over 1rpm or 2 rpm either side of 700rpm. It certainly isnt lacking any power and at idle there is absolutely no sign that I have blow by or excess gas/pressure. When the engine is cold or in regeneration, there is however the tell tale glug,glug,glug noise from the oil filler. A sure sign of a vacuum leak. Some of you may have noticed this noise when you've had a leaking engine mount. Imagine it at 2,200rpm with the oil filler cap on. I may be barking up the wrong tree, but there doesn't seem to be any inbetween. There's Euro4's that don't use a drop of oil and those that drink it by the bucket. I'm going to clamp off the line to the EGR Cooler Bypass valve and monitor the oil consumption. I'm also going to look into whether the engine could run on a C grade oil, with more frequent changes. If you're currently having similar problems with a Euro4, or have experienced them in the past, I'd love to hear your comments. I know it seems like a long shot, but logically it is possible. I will certainly know either way within a couple of weeks.

Wow, that’s a lot of words to read without paragraphs. Sorry, but it meant I didn’t bother. My loss I’m sure

[jamie1131]

Originally Posted by Nickthecook

Many have either sold or scrapped their Euro4 D5 after hitting a dead end in trying to resolve this problem. Firstly, if you're using the recommended 0w-30 A5/B5 and you're burning oil, theres a good chance your CAT is poisoned with Phosphors. This engine oil is not CAT and DPF friendly. But frst we need to understand why the Engine is consuming so much oil. I've read 100's of posts on various sites about D5 DPF's getting repeatedly blocked and the oil consumption as a result of almost continuous regenerations. Regenerations that never actually seem to clear the DPF. Many believe, because they've been told, that the oil burning is as a result of engine damage from bore wash. Bore wash can occur when a regeneration is interupted and diesel left in the cylinders can wash down the side of the pistons into the sump. They hypothesize that this causes wear and that gases are now blowing by the pistons, creating excessive crankcase pressure that forces oil through the breather into the induction system. This oil produces high levels of ash, due to the level of SAPS contained in it. Odd how every bit if information out there regarding OIL, CATs and DPF's, states that only a C grade should be used, as other grades will irreversibly damage the Catalyst and block the DPF and reduce it's lifespan. Ash can't be burned off like soot, it can only be physically cleared out. I agree in part with this, in that it is excessive crank case pressure that is responsible for the oil consumption. I don't however think it's being caused from blow by, at least not in all cases. After all, blow by isn't selective about when it choses to happen. This high oil consumption only occurs during regenerations and increases inline with the frequency of them. So what's different about a regeneration that could cause excessive crank case pressure? On the D5's fitted with the M66 box, is an EGR Cooler Bypass Valve. This valve is only in operation during engine warm up and Active Regenerations. It's purpose is to allow uncooled EGR gases back into the system to reduce engine warm up times and to help lift the exhaust gas temperatures during a regen. This valve is electronically controlled, but is physically opened by a Vacuum Actuator. (Volvo calls it a Vacuum Box) If this actuator is leaking badly and the valve fails to open, a) more soot produced as a result of slower engine warm up. b) an integral part of the regeneration process won't be working and as a result regeneration gases won't get as hot. c.) You won't get any warning or code as the actuator isn't monitored by the ECM. d) This is the bit that I 'THINK' is causing the oil problem. The Vacuum pump is going flat out trying to pull a Vacuum on the leaking actuator and the Vacuum pump vents Into the top of the Engine to be fed through the breather system. I've searched many diesel forums and discovered that Vacuum Pumps that vent this way can lift crank case pressures sufficiently for the car to start burning oil. One guys exhaust stopped smoking within a minute or so of him clamping a leaking vacuum hose. When I replaced the lifters on mine, the metal breather pipe that runs over the top of the rocker cover, was full of oil. My D5 has covered 226k, it ticks over 1rpm or 2 rpm either side of 700rpm. It certainly isnt lacking any power and at idle there is absolutely no sign that I have blow by or excess gas/pressure. When the engine is cold or in regeneration, there is however the tell tale glug,glug,glug noise from the oil filler. A sure sign of a vacuum leak. Some of you may have noticed this noise when you've had a leaking engine mount. Imagine it at 2,200rpm with the oil filler cap on. I may be barking up the wrong tree, but there doesn't seem to be any inbetween. There's Euro4's that don't use a drop of oil and those that drink it by the bucket. I'm going to clamp off the line to the EGR Cooler Bypass valve and monitor the oil consumption. I'm also going to look into whether the engine could run on a C grade oil, with more frequent changes. If you're currently having similar problems with a Euro4, or have experienced them in the past, I'd love to hear your comments. I know it seems like a long shot, but logically it is possible. I will certainly know either way within a couple of weeks.

I'd be interested to hear the outcome. I gave up on my 2007 XC90 after two independent garages told me the piston rings were knackered as a result of diesel contaminating the oil during regenerations. It was burning 2 litres of oil in 500 miles but had plenty of power and never smoked except after a long overun. I ran the crankcase breather to a catch tank instead of into the manifold but it didn't catch any oil at all and the smoke on overrun was still present.

[skyship007]

If your engine is in a bad way as a worn block, first of all try using Liqui Moly Ceratec (Half a can every OCI is enough) AND have a can of a major brand stop leak additive to help swell the valve guide oil seals.

If you don't want to use Ceratec and Stop leak, then move up to using a thicker high mileage oil. One of the best is Mobil 10w60 (A3/B4). Make sure it's the high mileage version, as they do make a race version.

Don't use a thin oil like Edge 0w30 or Mobil 0w40. The latter oil is classed as a low 40 and not much different in viscosity terms to Edge 0w30, as that approved oil is at the top of the 30 range.

[osullivant]

"This high oil consumption only occurs during regenerations and increases inline with the frequency of them."

I think this is not always the case, mine used oil and had blowby all of the time..... as have other peoples cars...

I listened to many theories and seemingly credible explanations for oil use, turbo, pcv, wrong oil, too much oil, etc etc I never smelled diesel from my oil or ever noticed an increase in the level....

I have nearly finished putting my xc90 back together after having oil usage problems.

The rings were in tatters. Bores were perfect, as were all the bearings.

I think the crud on the engine and around the rings was actually providing compression, it was when I cleaned the engine and started using good oil that my problems really started.

It is a lot of work, especially if you leave it for 3 months to start reassembly... and cannot find some tools etc....)( but relatively cheap on parts,( compared to new turbo) will not know for a few days the outcome subject to getting Wednesday to work on it....

fingers crossed

[skyship007]

Originally Posted by osullivant

"This high oil consumption only occurs during regenerations and increases inline with the frequency of them."

I think this is not always the case, mine used oil and had blowby all of the time..... as have other peoples cars...

I listened to many theories and seemingly credible explanations for oil use, turbo, pcv, wrong oil, too much oil, etc etc I never smelled diesel from my oil or ever noticed an increase in the level....

I have nearly finished putting my xc90 back together after having oil usage problems.

The rings were in tatters. Bores were perfect, as were all the bearings.

I think the crud on the engine and around the rings was actually providing compression, it was when I cleaned the engine and started using good oil that my problems really started.

It is a lot of work, especially if you leave it for 3 months to start reassembly... and cannot find some tools etc....)( but relatively cheap on parts,( compared to new turbo) will not know for a few days the outcome subject to getting Wednesday to work on it....

fingers crossed

Broken rings are fairly rare these days, worn out valve guide oils seals or HG failures are much more common.

Top end troubles often relate to poor oil flow caused by either varnish deposits or sludge. If your oil was changed at least every 10 to 15K km, then you can still get issues with varnish caused by overheating (Often thermostat, blocked oil cooler or air in coolant system), or from sludge in the oil pump intake screen caused by HG pinholes.
Anti freeze reacts with the Calcium and Magnesium compounds used as detergents in the oil causing them to fail in terms of cleaning and preventing clumps of Carbon forming in the oil.

[osullivant]

Originally Posted by skyship007

Broken rings are fairly rare these days, worn out valve guide oils seals or HG failures are much more common.

.....

Not broken rings... worn rings, to the point that the oil control rings were pretty flimsy, end gaps were larger and the width of the rings themselves was noticeably less than original.

Replacements were OEM German (Mahl). pistons still had the qr marks on them the original honing could be seen on the cylinders.

Going to use usual synthetic and change after 200 miles...

[skyship007]

Originally Posted by osullivant

Not broken rings... worn rings, to the point that the oil control rings were pretty flimsy, end gaps were larger and the width of the rings themselves was noticeably less than original.

Replacements were OEM German (Mahl). pistons still had the qr marks on them the original honing could be seen on the cylinders.

Going to use usual synthetic and change after 200 miles...

You said the rings were in tatters which I assumed meant broken. Mahl parts are real good.

If you are breaking a modern engine in there is no need to change the oil and filter more often than half the max recommended OCI. That half max limit used to be listed as the severe service interval. If you want to be extra careful, then using the Volvo SSI for hot desert or off roading makes sense.

Volvo still use 3000 miles as their OCI limit for some hot desert areas, but that is due to ultra fine Silicon particles that pass through the air filter and rings.
For my old donkey Volvo even recommend using a 15w40 full synthetic (A3/B4), even though Amsoil are the only company making one. What the dealers use is Castrol GTX 15w40 at present.

[Alen]

Hi , I'd be interested to hear the outcome too becuse having the same problem with my xc90.
Nickthecook, anything new?

My turbo was rebuild 3 months ago, and than a nightmare with oil consumption started.
Could a rebuild turbo make so much pressure that the car that was consuming 1l oil every 1800km before rebuild starts consuming 1l/200km.
The car had plenty of power before rebuild, did not smoke, and after rebuild no increase of power.

What about "low friction" oil rings introduced in 2007? Could they be the problem?