adeolly wrote: ↑
Sat Oct 06, 2018 7:17 pm
With regard to the oil dropping out of the viscosity bounds; any clues why? Is 2.7% dilution and/or the FE enough to do that, or do we just not know.
You've got it in one. SAE 30 oils are required to retain a "hot" (100 deg C) viscosity of between 9.3 and 12.4 cSt. The Castrol Edge Pro data sheet below shows a nominal viscosity of only 9.52 cSt although BP-Castrol told me it does vary a few points either side, while the sample of new oil I sent to Millers in July 2017 had a measured viscosity of 9.71 cSt. So, as 30 weight oils go, this isn't a particularly thick one to start with and just a few ml of diesel fuel will knock it down to SAE20. Your 2.7% dilution is equivalent to pouring 175 ml of neat diesel into a new charge of oil and this is what accounts for the 8.6 cSt viscosity found by Millers. Is that a big viscosity reduction? Is that a lot of diesel? Or is it really not that much? How long is a piece of string?
Whether or not the diluted oil by itself
is capable of damaging the engine is debateable. It's possible (probable, even) that modest dilution in the range of 2% to 5% (up to 325 ml in 6.5 litres) won't do any damage to a modern engine that has been built to single-digit micron tolerances (See The Micron Factory
) as this one apparently was. My own 2500 cc Toyota petrol engine runs on SAE20 as do plenty of other modern vehicles - though, come to think of it, I don't know whether there are any diesels. Maybe someone else can answer that one. So, maybe running on slightly thinner oil is no big deal. Perhaps JLR could easily have specified an SAE20. In that case, why didn't they?
This engine does have some bearing assemblies that might be extremely sensitive to loss of viscosity and I am thinking here about the balancer shafts in particular. They run at double engine speed and they are designed deliberately to create asymmetric loads on the crank case. The needle rollers of the balancer shaft bearings are constantly exposed to "out of balance" forces. Think about it: needle bearings (chosen for their high speed, rather than for their load-bearing properties), running permanently out of balance, spinning at up to 8,000 rpm. Oh, and they're not pressure fed with oil like the big ends, merely "misted" with un-pressurised, diluted lubricant. I am not saying that the diesel dilution effects on an already-thin oil is responsible for the high number of balancer shaft failures but it does make you wonder why there have been so many failures and the need for a JLR bulletin on the subject. So, maybe diluted oil is more damaging than it seemed at first...
There are very high traces of Iron and elevated Silicon - but Copper, Aluminium and Chromium are, to all intents and purposes, normal. What's going on in these engines that causes them to lose so much Iron, but none of the other, more typical, wear metals? It could be metal from piston rings (2 of these on each piston + 1 oil scraper ring), bore liners (cast Iron, would also explain the Silicon), piston skirts ("slapping" the bores during active regeneration) or, as already mentioned, high speed roller bearings on the balancer shafts or the 10 roller bearings that support the twin camshafts. I favour the bore liners but I have no supporting proof, just a hunch.
Is this amount of Iron a problem in the long term? No-one really knows. Will it diminish with time? No-one knows, all owners can do is monitor and hope for the best. I asked JLR a number of what I thought were sensible, precautionary questions at a time when my head was telling me this car could prove to be a liability but my heart was saying, "nah, it'll be alright, just take a chance and enjoy the best bits." Jaguar Land Rover said nothing. My head won the debate. These are the questions and, if JLR is reading this, I'm sure there will still be quite a few owners looking to hear something positive on this subject.
VeryDiscoSport wrote: ↑
Tue Aug 08, 2017 1:36 am
Please answer the following questions regarding the lubrication properties of the standard oil when subjected to these levels of diesel contamination:
a) What is the minimum viscosity at 100 degrees C (in centistokes, cSt) that the engine lubricant must maintain at all times in order to ensure adequate lubrication of all the moving parts?
b) Describe any test results that JLR has obtained to demonstrate the Ingenium engine's ability to withstand FIO dilution levels above 2% when starting with a new charge of SAE 0W-30 ACEA C2 / STJLR.03.5007 oil?
c) What is the expected useful service life of the 2.0 litre Ingenium turbo diesel when subjected to continuous cycles of oil dilution in line with the current software programming of the SIM? ( i.e. when FIO rises continuously from 0% to 6.1% every 10,000 miles, assuming STJLR.03.5007 oil is used)
d) Please provide guidance on wear metal levels that JLR consider would be acceptable to achieve the stated useful service life of the engine.
e) Regarding ways to compensate for loss of viscosity due to high FIO levels - What would be the maximum viscosity at 100 degrees C (in centistokes, cSt) of a synthetic multi-grade oil suitable for use in the Ingenium turbo diesel? (e.g. would it be acceptable to switch to SAE 0W-40 ?)
f) What, if any, fuel penalty would result from the use of such oil?
17MY DS150PS 6 speed manual. Rejected as "not of satisfactory quality", "not as described", Consumer Rights Act 2015.