J.R.

This makes no sense to me: The two oil pressure switches are monitored by the ECM. If the oil pressure exceeds a certain threshold, the ECM opens the correct oil pressure switch. This action transmits a message across the CAN-Bus, lighting the K3 Oil Pressure Indicator Lamp in the instrument cluster Should it not read "If the oil pressure exceeds a certain threshold the ECM it opens the correct relevant oil pressure switch.

An engine that is screwed is audible from a mile off to a deaf man. You say the engine is operating at 0.4 bar oil pressure but you only have the word of the main stealer for that, do not take anything anyone in the motor trade is telling you as a given without confirming it yourself, especially when they are hoping for a £9K payday. Checking the drained oil and the removed filter will tell you all you need to know about possible engine damage. Check the O rings on the filter stick while you are at it!

Make your mind up, whats it going to be, no insult at all, you were joking or you can assure me that you were not trying to be funny? You get to choose one, they are mutually exclusive. The easiest would be to behave correctly in the first place. No time like the present for starting.

So Num Nuts is no insult at all and despite you following it with a laughing smiley you can assure me you were not trying to be funny, so what does that leave then? Not to mention the "so-called brains and know it all on here, clearly do not have a clue about what happens in the real world outside their ivory towers." I would simply be happy if you would refrain from the personal insults, as a bonus we would not have to suffer the subsequent denials.

Yes it can be repaired if you have good soldering skills, suitable equipment and are experienced in prying apart small plastic assemblies that were not intended to be disassembled. Some people offer it as a service you might even be able to tempt @Breezy_Pete

That should be the responsibility of any responsible owner/driver. Its far more likely to be an excuse to make a sale through scare tactics or charge through the nose for topping up oil or fluids that may have been at the correct level, is it really worth your time to be a willing victim?

Inactive after ignition switched off, a red herring. Does your 2012 vehicle have a DPF? The fans will run on after shutdown if a regen is interrupted but should stop after 10 minutes. I would find and test the fan relay, it sounds like the contacts may be fused together, it may be part of a controller but hopefully will be seperate, others with knowledge of the model will I hope advise.

Please stop with the insults. I too did 8 years day release to finish with an HND but it was and is a 4 year day release course hence my asking if you were slow. In my case I was immature at 16 and being alone in the world without parents went off the rails, I failed N1 and the lecturers, rightly in hindsight, refused to let me retake, in reality refused to have me back in their classes. I dropped down to Technicians 2, well below my actual capabilities, then had to go through T3 and T4 and T5 get a Full Tech Cert then do a years bridging course to get onto N3 where I should have been at 17 but was now 22 and karma meant now had to put up with other 17 year old immature versions of me disrupting the class, I was 24 before I got the HND I should have had at 20.

8 years for an HND, were you a slow learner? I have an OBeng 😀

And you never came in before the drivers to light fires to warm the engines and sweep the floor, did someone hack your account or did you just make it up?

Give me a couple of months and I will quote you on that and you can deny ever saying it like Graham.

He lit rags to warm up the fuel tanks of diesel buses before they went out on cold mornings and swept the floor. You only held your breath for 30 minutes, you let me down 😒

Switch off the aircon and see if the noise stops.

It could well be if you had to give it the good news with a hammer and chisel. Mine failed after clipping a kerb, what can happen is that the ferrite magnet enclosed in the plastic casing fractures and the signal generated is significantly reduced, did you replace it with a genuine part? I fitted the cheapest Ali-Express pattern parts, they were less than an Euro each, the one fitted works fine but I had low expectations, turned out it was worth the punt. At least with VCDS or similar you would know if the fault is with that wheel sensor, possibly the connector.

If I were at my main residence where I have a printer I would have printed out the self study guide as bedtime reading, these vehicles are getting so complicated that we need to bone up and have knowledge if not experience in advance of being faced with our first new problems.

Could be related but only a one on four chance that it would have been that wheel speed sensor, you really need to check with something like VCDS where you can look at live data and see any intermittent bad signals. You dont need to delete the fault codes for the dash lights to go out but if a sensor is still bad they will come on again on each start up or during the journey if intermittent.

And I was so looking forward to witnessing end stage grief! I have a feeling that unlike you Graham when wyx087 says he is not going to respond any further that is what he will do or he will at least pause for breath.

A question for @TheClient Having read through the first page again and understanding more about the dual pressure oil pump and the piston cooling circuit could another possibility be that the solenoid valve for the piston cooling circuit is stuck open and hence there is too much pressure drop during the lower pressure output? The extracts from the self study guide spoke about reduced oil pump speed, that would concur with the above suggestion if its the pump speed that is reduced rather than its output pressure via a PRV but how do they acheive different gearing to the pump? It doesn't explain how and the front mounted one looks to be driven from the poly-V accessory drive belt.

It will be very interesting and I hope rewarding to hear the news.

You are confusing efficiency (getting the most power output from a given calorific fuel input) with lower fuel consumption, generally the slower you drive the less fuel will be used, the main reason being that drag is proportional to the square of velocity, you will consume less fuel driving at 1500 rpm in top gear, say 40mph than you will at say 55mph and 2000rpm but the engine will be burning fuel more efficiently at the higher RPM, producing more power per unit of fuel but also using far more of that power to overcome drag, reciprocating and rotational losses. The text of mine you quoted was not clear in isolation, it should be read together with the other words speaking of the maximum efficiency being at max torque RPM on max power, typically on an engine brake dyno or accelerating during an overtake (hence my speaking of transient), I did say at 3K RPM for my vehicle in the text you quoted, that is a long way from maximum RPM, I rarely exceed that 3k rpm and only when overtaking etc, my cruising is between 1200 and 2200 rpm. https://www.facebook.com/photo/?fbid=2679051228845565&set=pcb.2679052015512153 https://www.facebook.com/CelticTuningHome/posts/skoda-yeti-20-tdi-108bhp-up-to-186bhpa-skoda-yeti-5l-on-the-dyno-with-the-20-tdi/2679052015512153/

It makes me wonder if the previous owner was faced with a similar diagnosis and quote? I have bought cheap many cars with problems that I have eventually resolved by determination and a lot of mental effort, in every case they had been sold on and on making their way through the trade to private owners and back again a few times before they ended up with me, the cheap buyer of expensive problems! I have seen some misdiagnosis and scary quotes in my time all of which missed the actual fault caused by the servicing dealers incompetence but £9K for a missing O ring if that is the case here takes it to a new level, its 100% believable sadly and I really hope that it is the case for the OP.

I suspect the valves main function is to bypass the oil filter if it is clogged and has a neat secondary fuction of retaining the oil in the inverted filter and allowing it to drain down as the filter is being removed. On my next oil change I am going to unscrew the housing until I feel the O rings release then go for a cup of coffee, hopefully then for the first time in 3 decades the old filter will not drop oil everywhere. I think I will owe a debt of gratitude to TheClient! Editted, later spring loaded shaft is almost certainly for clogged filter by pass, I can't see how the solid one can acheive that unless there is an internal spring, as they are interchangeable (with new plastic housing) then there cannot be a seperate one built in to the earlier oil pumps.

I dont think mine has the spring, you can feel when tightening and loosening when the O rings are forced into the bore, I think there is at least 10mm of engagement, a spring loaded one seems like a backwards step but perhaps there were other issues perhaps with the O rings becoming displaced, thats another reason I started leaving the old ones in place if they were undamaged, some of the new ones even on VAG filters from TPS were very resistant to enter the bore and required too much tightening torque, I was concerned they might get damaged or displaced. Why are there two of different diameters, - belt and braces?

Having done more oil changes on my VAG TDi's than I have had hot dinners I am very familiar with the stick and O rings but to my shame I had not appreciated its function as an anti-drain valve until now. I gave up replacing the O rings some while back settling for a visual inspection due to the frequency of oil changes, now I know whats at stake I will be looking very carefully.

From my very rough and ready tests a diesel engine would do the same but neither would be able to cover any significant distance at 20mph without stopping and restarting frequently at which point the EV has a massive advantage. I have ignored petrol engines as they are capable of being abused in the same manner driving at tickover in the highest gear including up hills.