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jtq4u

Member Since: 23 Aug 2023
Location: Portsmouth
Posts: 37

2011 Range Rover Vogue 4.4 V8 Stornoway Grey

Oil analysis after a 'service required' message

Click image to enlarge

Hi all,

I got a 'service required' message last week after just 3,000 miles on the oil.
This is likely related to the battles I have been having with the DPF.
Anyhow I wanted to know how truthful the car's opinion was on needing an oil change so I took the plunge and paid for an oil analysis.
I attach it in case anyone is interested.

It says it is a negative for Fuel dilution. However it also shows that my oil is out of specification slightly.. it is around a 0W25 oil now, after 3000 miles. Of course we don't know how accurate the Westway 0W30 oil was in the first place.
It probably isn't far enough out of spec to require the oil change right now
If I had an infinite amount of money I would test:
- some brand new Westway oil
- Some oil with a deliberate 7% diesel mixed in (to see if the test center notices it)
- Some oil at the end of a full year's use.

21st Sep 2023 3:13pm

JayGee

Member Since: 27 Jul 2021
Location: London
Posts: 3200

2012 Range Rover Vogue 4.4 V8 Orkney Grey

I'd either take this up with Westway or choose a different oil ( or both). Have you had excessive oil use or smoke from the 2nd turbo? How much was the oil analysis BTW? 2012 TDV8 Vogue (L322)

21st Sep 2023 3:32pm

jtq4u

Member Since: 23 Aug 2023
Location: Portsmouth
Posts: 37

I don't think I can immediately blame westway, as I don't know for sure if the oil analysis company is right in saying there is no fuel dilution.

If there was oil in the fuel it would have reduced the viscosity. To be sure I'd have had to send some brand new oil to them for analysis. But of course that would then double my cost

cost of the analysis was £37.80 from aaoil.co.uk

I guess I might not see any smoke, because the DPF would capture it I think?

I do still have on my to-do list performing a high pressure leak test post turbo. I just need to find somewhere local and reasonably priced.. or make up a piece of kit myself.

21st Sep 2023 4:25pm

JayGee

Member Since: 27 Jul 2021
Location: London
Posts: 3200

I think it's safe to assume the oil analysis company can tell if there is fuel in the oil - why would you think they can't if they can do everything else. The DPF captures soot ( particles of carbon) and the 'smoke' from the 2nd turbo is actually oil vapour so it easily passes through the dpf 2012 TDV8 Vogue (L322)

21st Sep 2023 4:34pm

jtq4u

Member Since: 23 Aug 2023
Location: Portsmouth
Posts: 37

Fair point about the oil analysis company I guess.
I wonder how quickly oil normally changes from its original viscosity - I have no idea!
The fact they have flagged it up suggests it is significant. Maybe I should ask westway what their oil starts off at. As I said, if I had the money and inclination I'd send some new oil for testing.

No oil/smoke coming out the exhaust. Always nice and invisible.

James

21st Sep 2023 4:59pm

JayGee

Member Since: 27 Jul 2021
Location: London
Posts: 3200

It should hold it's viscosity. It gets thicker as the soot load increases and thinner as the fuel contaminates it so there is some kind of equilibrium. I'd maybe be slightly concerned with the iron content as a thinner than stock oil may not provide the correct separation of moving parts esp on a high mileage engine where it's sometimes beneficial to run a slightly thicker oil. 2012 TDV8 Vogue (L322)

21st Sep 2023 5:03pm

garyRR

Member Since: 13 Mar 2021
Location: Hampshire
Posts: 1465

Your DPF issues - I trust you've followed all the usual causes:

- 2x charge hoses
- 4x donut hoses
- throttle body seal
- smoke test for intake leaks/cracks

- drive the car on the M27 once a week

...also, did the garage forget to reset your service interval? This sounds like the most likely cause of the message to me.

Grade of oil used or specification or oil used I'd also question. 2015 Range Rover Autobiography 4.4 SDV8

22nd Sep 2023 6:51am

garyRR

Member Since: 13 Mar 2021
Location: Hampshire
Posts: 1465

22nd Sep 2023 7:08am

jtq4u

Member Since: 23 Aug 2023
Location: Portsmouth
Posts: 37

JayGee wrote:
I think it's safe to assume the oil analysis company can tell if there is fuel in the oil - why would you think they can't if they can do everything else. The DPF captures soot ( particles of carbon) and the 'smoke' from the 2nd turbo is actually oil vapour so it easily passes through the dpf

As it turns out it wasn't so safe after all

The uk analysis company outsources the lab work to a UK company, and then the production of meaningful results to a US company. I found the bloke in the US who actually wrote my oil report and he has said that the UK company wrongly tested for petrol in the oil instead of diesel.
He also said that therefor the likelihood is that both the reduction in viscosity and the iron levels are down to diesel fuel dilution. I will of course be following up with a complaint to the company who took my money.

22nd Sep 2023 8:41am

jtq4u

Member Since: 23 Aug 2023
Location: Portsmouth
Posts: 37

garyRR wrote:
Your DPF issues - I trust you've followed all the usual causes:

- 2x charge hoses
- 4x donut hoses
- throttle body seal
- smoke test for intake leaks/cracks

- drive the car on the M27 once a week

...also, did the garage forget to reset your service interval? This sounds like the most likely cause of the message to me.

Grade of oil used or specification or oil used I'd also question.

I have visually inspected everything, but not yet had a high pressure smoke test, as I need to find someone local and reasonable in price to do it. I may get round to making a piece of kit myself, and doing it (but the wife generally has less interesting things to assign to my time!).

Sadly most of the driving is already on the M27! probably 70% of it is at 50 to 70 mph.
last week I did 120 miles to work and back >50mph. I started at 0g soot and finished at 17g soot (and a request for regen.. too late of course as I have now finished my trips on the motor way for the week).

I reset the service data after changing the oil back in May.. 3000 miles ago. But as we now know the car is right to be requesting an oil change most likely.

22nd Sep 2023 8:45am

JayGee

Member Since: 27 Jul 2021
Location: London
Posts: 3200

Glenrands is just up the A3 from you. Suggest you book it in and they will sort it for you 2012 TDV8 Vogue (L322)

22nd Sep 2023 8:59am

DrRob

Member Since: 16 Apr 2015
Location: Petersfield, Hampshire
Posts: 4302

2011 Range Rover Vogue SE TDV8 Buckingham Blue

Ditto that. Drop it off with Ross and the lads. They have a smoke tester and full LR main dealer level diagnostics and excellent technicians. Tell them I sent you
Mine is there currently have a new air con rad, lower front arms and a small oil leak investigated...
They do loan cars... Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

22nd Sep 2023 9:02am

jtq4u

Member Since: 23 Aug 2023
Location: Portsmouth
Posts: 37

As someone with a scientific background I decided there must be a way to calculate the viscosity of a blend of two liquids and it turns out there is of course.

So I have done the calculations for what a liquid made up of 93% oil and 7% diesel is.

The answer is 8.0 cSt

so my oil is very close to 7% oil dilution
(range rover's max acceptable value for that year.. they did, for better or for worse recode it to 10% I think in later years - probably just to stop people complaining about oil changes, rather than for it being OK).

if you want your mind blown, or love maths.. here are my workings to check

https://citizendium.org/wiki/Liquid_viscos...%20(loge).

VBN = 14.534 × ln[ln(v + 0.8)] + 10.975

VBNBlend = [wA × VBNA] + [wB × VBNB]

            e(VBN - 10.975) ÷ 14.534    

v blend = e^                            − 0.8

https://www.researchgate.net/publication/35461426_Fuel-Lubricant_Interactions_Critical_Review_of_Recent_Work

shows the viscocity of diesel at 100 degrees is 1.28 cSt

the lowest acceptable viscocity of 5W30 oil is 9.77 cSt

lets put the values into the equation at 7% dilution:

VBA = 14.534 × ln[ln(9.77 + 0.8)] + 10.975 

VBA = 14.534 × ln[2.358] + 10.975 

VBA = 14.534 × 0.8578 + 10.975 

VBA = 12.468 + 10.975

VBA = 23.4426              23.442587839924595639895981511893

VBB = 14.534 × ln[ln(2.08)] + 10.975 = 

VBB = 14.534 × ln[0.7324] + 10.975 = 

VBB = 14.534 × -0.3115 + 10.975 = 

VBB = -4.527 + 10.975

VBB = 6.4481              6.4480615302417669052839795265684

VBNBlend = [0.93 × VBA] + [0.07 × VBB]

VBNBlend = [0.93 × 23.4426] + [0.07 × 6.4481]

VBNBlend = [21.8016] + [0.4514]

VBNBlend = 22.2530

      e((VBN - 10.975) ÷ 14.534)     

v = e^                            − 0.8

      e((22.2530 - 10.975) ÷ 14.534)    

v = e^                               − 0.8

      e(11.2780 ÷ 14.534)    

v = e^                            − 0.8

      e(0.7760)    

v = e^                            − 0.8

      2.1727   

v = e^                            − 0.8

v = 8.781981486777                    − 0.8

v= 7.982

so a viscosity of 8.0 relates to an oil dilution of 7%

22nd Sep 2023 9:11am

jtq4u

Member Since: 23 Aug 2023
Location: Portsmouth
Posts: 37

DrRob wrote:
Ditto that. Drop it off with Ross and the lads. They have a smoke tester and full LR main dealer level diagnostics and excellent technicians. Tell them I sent you
Mine is there currently have a new air con rad, lower front arms and a small oil leak investigated...
They do loan cars...

Cool, thanks for the reference, I'll get in contact with them and see how much they charge for a smoke test.
I'll also ask if my father in laws friend who works at a land rover specialist in east devon does such tests. He might of course charge my favorite price of 'free'

22nd Sep 2023 9:14am

JayGee

Member Since: 27 Jul 2021
Location: London
Posts: 3200

jtq4u wrote:
As someone with a scientific background I decided there must be a way to calculate the viscosity of a blend of two liquids and it turns out there is of course.

So I have done the calculations for what a liquid made up of 93% oil and 7% diesel is.

The answer is 8.0 cSt

You need also to factor in the soot content and it's viscosity increase 2012 TDV8 Vogue (L322)

22nd Sep 2023 9:58am

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