Hi Guys,

I'm shortly going to service my 2011 Octavia MK II, changing oil, oil filter, air filter, pollen filter, fuel filter and plugs.

I have read up on resetting the Service Interval indicator (holding in the trip odometer etc.) but do I need to get someone with a VCDS to do any service resets with that?

 

Originally I thought I'd be fine but I have been reading various threads re: VCDS and seen mention of oil quality in the settings.

WIll my clever Octy detect the new oil (and hence it's smashing super duper quality) or will it need to be told about it?

Cheers.

I think (I may be wrong) it depends if the car is on variable service of fixed. Resetting the service indicator by the trip odometer button will set the car to fixed, If you plan on doing the services yourself just reset the indicator as above. Use the best oil you can and change it regularly. There is a sensor in the sump so it basically knows when the oil is past its best, You don't need VCDS. I use Quantum oil which is supposed to be what Skoda uses and good quality filters from ECP.. 

Edited 24 August, 20205 yr by Doofy

Thanks for that. 👍

I dont believe that the sump sensor actually measures the oil quality but happy to learn otherwise, I think it measures the level and the temperature, and there is an algorithm that calculates the oil quality by using the temperature input, the miles driven, the speed, the throttle opening, EGR, regens etc etc etc.

 

And we all have 100% confidence in algorithms dont we

 

Happy to be corrected.

7 hours ago, J.R. said:

... think it measures the level and the temperature, and there is an algorithm that calculates the oil quality by using the temperature input, the miles driven, the speed, the throttle opening, EGR, regens etc etc etc.....

More good info.

But surely (don't call me Shirley!) that would be prone to error as you could bung some cheapo Halfords slop in or alternatively some top grade stuff and the pesky algorithm would come up with the same result without actually "tasting" the oil?

 

Either way I'm happy to go onto fixed servicing (via the service reset method). 👍

An oil that did a worse job of lubrication would result in it (the oil) getting hotter, wouldn't it? In which case the temperature sensor would 'taste' it.

 

Shirley no garage would do that.

10 hours ago, Wino said:

An oil that did a worse job of lubrication would result in it (the oil) getting hotter, wouldn't it? In which case the temperature sensor would 'taste' it.

 

In theory, yes, but the temp rise could be -0.1 C and that still represent damage. And, if the temperature did go up ~10 C, but the engine hadn't yet got up to temperature, would it detect that? And, if something changed the engine cooling (failed thermostat/edge of tolerance thermostat, blocked radiator, etc) that would probably throw up deceptive codes. And, if the oil viscosity was even slightly different (or antifreeze conc changed slightly) then cooling would change more than the minute amount that a small bit of friction would cause. (Or, old oil...or a different brand of oil, or, in some cases, a mix of oils)

 

To summarise: that's not how it works.

So how does it work?

@Axle_of_weasels, you did realise that I was referring to the oil temperature, as measured by the oil level/temp sensor in the sump, rather than coolant temperature, right?

Edited 25 August, 20205 yr by Wino

Yes.

So you've got nothing by way of alternative explanations? ☺️

Seems a bit lame considering how confidently you rubbished my post.

It works like religion, people believe what they want to believe.

 

When you think about it VAG introduced variable service limits years ago when all it meant was car A's service indicator came on at a lower mileage or earlier than car B and often the driving styles of Mrs A & Mr B would have suggested the opposite.

 

Then the guys who think up nonsensical names for algorithm generated variables in VCDS came up with "Oil quality" its not a real measuring block like coolant or oil temperature, more akin to the AC compressor load which is just a calculated figure and does not even know that the shear plate has let go and the compressor is seized solid.

You asked a question, and I answered. I was in a bit of a rush at the time.

 

OK, so this is a bit less lame, then.

 

It is an algorithm that scores different conditions. So, when the oil is really hot, it accumulates points at a higher rate. Possibly, high load/accelerator values add to the rate at which points are added, although with the oil temperature already there, I'm not at all sure that is necessary. Possibly, you add points for every cold start, as there will be a tendency to accumulate crud and moisture. The moisture points, if any, would be cancelled on the next extended hot run.

 

These points are then used to predict oil life and when you reach some threshold, the oil is over. Given the variability in all of this, you'd probably need a margin, but with the lack of transparency, most people won't have the evidence to complain, provided it is more or less right, most of the time, and tends towards the conservative side.

 

As big an issue is the oil specification. IIRC, it dates from the late 90s, when some of the tricks used in current Oil Design weren't in common use, and while that isn't necessarily a problem, it does mean that the scoring isn't necessarily as accurate for today's oils as it was for the oils of the day. Originally, only two or three oil companies were in the program of oil development to the new spec., and there was then some dropping out, which I think only left one or two companies in, at introduction.

 

Since then, oil technology has come along to the point where most oil producers could produce to the variable life specs, even if some don't feel that the economics are attractive. 

Better.