TheClient

Yes, will do. I am expecting a bit more throttle response. And smoother cold start driving. Maybe fuel economy back up a little would be good too!. It has seemed to get worse lately. Main reason for undertaking this work is that when cold, under very light throttle, I can detect a slight miss until the engine warms up a bit. Didn't throw any codes and it only started in the last month or so. Seems quite consistent with the carbon clogging of the valves and ports symptoms. Finger crossed after all the trouble and the injector clean and tests it will be gone...the fault symptom that is....

Well. I have not yet re-assembled! So far. On 1 day probably about 3 or 4 hours disassembly then 2 hours or so cleaning. Today another 1 hour cleaning (i'm much better at it now). Throttle body cleaned as well but that was nothing like the valve or ports. Re-assembly? Hopefully 2 hours. But if you have done it a few times that would come down a lot. As I am working on a drive and that includes jacking up car, removing undertray, climbing underneath and back out and back under whilst scratching head... Repeat. You get the idea!

So I have finally had to do what I was trying to avoid. Odo has nearly clicked 69k miles. Mixed urban and longer runs. I've had car last 35k miles so highly unlikely it has been done, and no signs of inlet manifold or charge pipes having every been removed before. Waiting for the injectors to come back after cleaning and testing. Hopefully put it back together on Friday. Fingers crossed. It wasn't as bad as I thought it might be. I went very slow and watched a few videos before hand. The worst bit by far is the inlet manifold nose bracket the M10 Spline is a nightmare to reach. Not looking forward to that on re-assembly.....

So I've turned my hand to a bit of intake valve cleaning. I can confirm the line you refer to in blue is a vacuum line between turbo and intake manifold. It may be an equalisation or pressure relief or just vacuum but defn not fuel or oil.

Put a new wiper blade on or operate it flipped off the screen. Does it still make noises other than the hum of the motor and gears? If so there is a problem! There is no constant on for mine. When it is on, it is on an intermittent setting swiping back and forward every few seconds.

Should be ok based on that 2017 production date. I don't have access to the serial numbers to check component build of the base engine.

Oil build up on the turbo intake tract is not uncommon. I had it quite noticeably when I bought mine in 2016. I cleaned it and it came back. I was also getting quite a lot of oil discharge from the underside of the turbo. I posted a detailed thread and detailed photos. In the end the thing that appears to have cleaned that all up was indeed a new fine oil separator / pcv. Also, it is not entirely uncommon to need to add some oil to the CCZA. If that is done without care, it will spill in the rubber funnel around the oil cap and if not removed will either spill over the top down onto the rocker cover or seep down onto the rocker cover. It that happens a few times or one careless oil top up it will deposit oil on the rocker cover with no where to go. I'd have a good look round for any other evidence of source then thoroughly clean it up. I'm not sure about that pipe you refer to. It looks black plastic or rubber, which would eliminate an oil line. It is not shown on the schematic for the turbo feeds and return. See link below, my guess is either vacuum or coolant. I've also attached the coolant schematic see if anything looks familiar. Are you sure it actually interconnects into an oil cooler? If so, transmission oil cooler or engine? https://skoda.7zap.com/en/cz/octavia/oct/2010-663/1/145-145075/ https://skoda.7zap.com/en/cz/octavia/oct/2010-663/1/121-121027/

How does boost hold up when the problem occurs. If you have vcds do some logging to include specified and actual boost when the fault is occurring.

Comes up a lot. Lots of threads on here asking the same question. Best to talk of engine series, EA113 (main timing belt drive) vs EA888 (main timing chain). EA888 is the later design, seen in the facelift Octavia 2s. Or use engine codes - BWA (earlier) or CCZA (facelift). Forget TFSI vs TSI. The facelift was badged Tsi but in registration and official documents it says TFSI - both are just marketing terms and mean the same thing anyway..... Both had certain problems. Possibly the EA888 is the most prone to meltdown due to the timing chain tensioner losing tension. Latest revision tensioner and chain is a must IMO. Also can suffer from piston scraper ring clogging which eventually causes a lot of oil usage but not all are impacted. Long life extended miles servicing can make it more prone to problems. Time and distance preferred.

Mmm. That's the trouble with EA888 engines, they are complicated beasts when they do not operate correctly. I will have to review everything you said again, as clearly you have focussed on the usual suspects. The diverter shouldn't be operating from 2,000 rpm should it. My instant reaction is a turbo problem, the wastegate bushings are not that fantastic on the IHI installed in stock. What is your mileage?

Good point. I'm living 9 years in the past! Don't have a car with R1234YF gas yet. So, although you can obviously do most of the service items yourself, cheaper, with an underlying zero labour rate, the Skoda prices don't look insulting IMO. As long as you get a decent Skoda tech actually working on the car.

Is it in warranty? It sounds like it might be? Id so, you need to be "careful" that the documented regime is followed, whether at a dealer or specialist. And keep records. As @e-Roottoot there is lots of service regime information published, not all totally consistent. So. You need an oil and oil filter change minimum. If it is due the plugs (what is the age ?) £99 is not ridiculous. The plugs part cost alone at a dealer part dep are £40 to £50. Same with brake fluid and extended scope checking. Yes, it will be cheaper if you can do it yourself but the prices don't look insane. I do brake fluid change but you have to jack the car up, buy a pressure filler or have an assistant, deal with stuck nipples etc. Dispose of brake fluid. It is not a 5 min job. The Aircon service does look very eeeeexepensive. There are lots of places that can do a decent job of this, for a lot less money. I usually pay £30 to £40. Anyone with dealer level or specialist diagnostics can put your car back on to time and distance servicing and it is generally the best for the cars health.

@Eddie-NL knows his stuff. I'd call him a master tech when it comes to electronic modules. Good result for you someone was able to check what they should of done in the first place!

I'd say it seems fairly likely to be related. I'd disconnect battery and remove cover and let it dry out for starters. A hairdryer on low/med temp will help speed up process.