Advice for novice re D5 Euro 4 losing oil

[D5meister]

I spoke with oil apps guy at shel or castrol few years ago.

He said as modern engines have such tight tolerances the worst thing is if u put say a 15w or 20w in a 0w engine it will irreversibly open it up then 0w won't work in it any more.

I started using 5w at about 150k rightly or wrongly.

It sounds OK and has never required a top up between annual changes from new.

Doing 14k per year.

Returns in excess of 55mpg 163hp 03 plate

[Rossi-fan]

Originally Posted by GrahamBrown1

what makes you say its to thin? When I was reading up online about this as my euro 4 likes a drink of oil the various sites that explained the spec say that 0 30 oils are not thin and contain good wear additives ect. Im not an oil person so im not criticizing you im just interested in your comments that all

Hi Graham. I'm no oil expert myself, its just what I've picked up over the years. A combination of Taking advice from time served spanner people, talking to my stateside pal Georgeandkira, reading up on things, and finally changing to a 'Heavier' number, and actually hearing a difference is where I draw my conclusions from.

[Nickthecook]

The oil will be burning through the crankcase breather system. One area that will increase the problem is the 'EGR cooler Bypass Valve Actuator.' A vaccum leak here will increase crankcase pressure. This is because the vent for the Vac Pump is in the end of the pump drive shaft, which slots into the end of the exhaust camshaft. Unlike the vac mounts where the Vaccum shuts off at 1,000 rpm, the actuator will remain open throughout the entire rev range and is in use during warm up and regeneration.

I have a theory that when these Euro4's start to use a little oil, it sets off a chain reaction that sees more frequent regenerations and an ever increasing oil consumption. As has been mentioned above, the oil is cooling the engine during regeneration, this means the oil temperature climbs significantly, to the point where the oil is burning off at a very high rate. This oil vapour (too hot and too much of it) overwhelms the separator and is fed into the induction system to be burned as fuel. Oil leaves a far higher ash residue behind than diesel, this restricts the flow of hot gases throught the DPF, which increases the frequency of regenerations, which burns more oil and so on. If you add into this the likely hood of interupted regens and bore wash contaminiating the oil with diesel, the oil/derv cocktail is thinner than the engine oil and of course, burns faster during Regen and now burns off during normal driving, which means more regens and........ You get the picture? I'm fairly sure the position of the oil cooler wasn't thought out very well either. Back of the engine and not all that far from the Cat and DPF. With repective temps in the region of 360°c & 750°c. and we want our oil kept under 90°c. Once that DPF becomes restricted, the heat starts to soak back through the exhaust during regeneration.

So basically, once you start burning oil in a Euro4, expect to burn a whole lot more.

Ideas for a solution, I've considered installing a catch can. Although the other tips below may help reduce oil consumption, the fact remains that very little oil consumption can set off a chain reaction making a catch can probably the best solution to reducing the amount of oil entering the induction system. Maybe a 5W40 A5/B5 or C3, but fuel economy will drop, as will performace. Not sure what the turbo will make of it either, although being water cooled surely helps. Fitting a heat shield to deflect regeneration heat away from the oil cooler, or retro fit the cooler elsewhere to avoid it becoming an oil heater during regeneration.

Regeneration is without doubt responsible for the euro4's oil consumption problem. I just don't believe the usual 'worn rings from bore wash, theory.' This is related to oil temperatures during regeneration and the chain reaction that is set off when the first drop of oil is burned. Of couse driving styles play a significant part in all this, low stress motorway miles with little boost and excellent airflow, helps to remove heat from the engine bay, keeping oil temps down. Stop start, local driving with frequent gas/brake will increase the need for regens and therefore oil consumption. Give that turbo a couple of full spools on a warm day during a regeneration and see that coolant temp shoot up. Pushed mine from 92°C to 110°C with 3 x low revs, high gear, foot to the floor moves today.

Things you can do. Clean the EGR valve regulary. This helps lower combustion temperatures. Use an ElLM327 obd2 dongle to see when the car is in regen. This way you can decide to either continue driving until the regen is complete, or at least wait until the ECM pauses the process, which is usually within 1-2 minutes of revs dropping to tickover, the valve closes (100%) When in regeneration, the EGR is fixed at 94.9% (95% on VIDA) Shutting off the engine during regeneration, will see some post injected diesel, wash past the rings into the sump and dilutes the oil. One must also consider the condition of the oil as the regeneration frequency increases. The oil that has remained, has still been subjected to some serious heat. Find a way to keep the oil temp down during regeneration and you'll solve your problem. That's not to say you'll never use another drop of oil, but it will no longer need topping up weekly.