BlueWagon

I wouldn't if the fans work and aren't noisy (bearing noise). Mid range maybe ok, or look at a more reputable brand on Skoda part net

Do this, before it gets to 120 degrees preferably....maybe as soon as it starts to rise over 100 Id spin the fan by hand and make sure there isn't something jambing it. Maybe string or something wrapped around it close to the shaft Maybe it needs new bearings or you may be able to lubricate the fan bearing with a squirt of WD40 as a very stop gap solution. Need to open up the bearing cover so that may be hard work/poor access. Replace fan motor??

Is the new PCV installed correctly and is it a good or genuine one. If a cheap ebay rip-off it may still be letting alot of oil past More likely oil entering combustion chamber. Oil or soot? If Oil, then its probably not the poor fuel ratio, maybe the poor AF ratio and injection codes are a symptom of Oil getting onto the O2 sensor If it was soot, then its all about the AF ratio

This is what I meanted

Sorry meant to highlight digital Is that not the oil temp....no reason they need to be the same.... Also, most water temp guages are "damped" to stop them fluctuating and making owners sacred

Leaking pipe, maybe external to the cab. But a pipe/hose isolated by the heater valve/pump during normal no heater operation. How do you know it is leaking from here? Have you ever actually seen it leak coolant from the overflow or the cap?

10 seconds of cranking...must be a half decent battery still unless it was cranking very slowly

Sounds like a bit of valve train rattle. Change the oil and make sure grade is correct. Maybe a noisy cam phaser or something but seeing as it goes away, probably just a bit of wear. Hell, plenty of engines used to tick and rattle when cold. My old 18R toyota motor was terrible for it. Still ran fine, just rattled when cold

So it does it at 90, or before it gets to 90? Because thos makes it sound like it doesn't happen if it is warmed up to 90? So how long before 90 does it run rough? Eg, when you first start or say 5 minutes after? Can you explain the sparodic problem? Why exactly did you change it? So are you saying every time between 80 and 90 it runs rough but you can still do 140 kmh no problem? I would avoid just changing parts without good reasoning because it will cost you alot and unlikely to fix much. Really need to do some diagnostic work. For example, next time it runs rough, try stopping and seeing if it idles or you can rev it freely in neutral? Try turning the engine off and restart and see if that helps? Does it blow black (or white) smoke when running rough?

Maybe an aluminium crush washer or O ring? You can put the oil you drain from the box back in if its very fresh. Just make sure you drain into a clean container

I have not removed one but if you are saying the pulley turns and this the engine turns when you try to undo the bolt, maybe try locking the engine up. If manual try in gear with handbrake on. If auto or dsg need to use a breaker bar on the crank pulley

Grab a few sizes and see what fits. If 40 doesn't, try 45. If too loose, try 43. T45 rings a bell for me but you are the one looking at your car. You are best placed to choose the correct size

Do you mean the stick won't move into the right position for 5th and Rev? Maybe a wasp or rat nest blocking the shifter on the box. Have a look while someone moves the stick inside. Maybe a bit of wd40 on selection cables too

Can you select these gears with engine off? Maybe clutch just a bit gummy so won't let you push into the gear. Maybe ride the clutch a bit to clean up the plates

I would and certainly do on any car I have the clutch out of. Also replace spigot bearing and thrust bearing