Breezy_Pete

Not a bad plan. Position 15, bottom right on the relay plate.

Oh excellent, well done.

So is it fixed? With a new crank sensor?

I wouldn't bother with WD40, if it does anything useful it won't last, and I very much doubt it will. The new lock should be greased in all the places that require it. Have you checked for broken wires in the hinge area of the door? Very common failure on mk2s. Might save yourself a fruitless lock change if you check that first.

Check that engine bay fuse number 27 (50 amps) for the glowplug module is intact, and not loose in its contacts. There are separate output pins/wires from the module for each glowplug, so it seems improbable that all of the wires have broken. Two thin control wires to the engine ECU could be worth continuity checking end to end. Pin 10 on module to 30 on ECU, pin 9 to ECU pin 63. After that, if no contact corrosion at the module connector, substitute another glowplug module in and see if those faults vanish. The modules are solid state, with no relay contacts to wear out, so a secondhand/scrappie one ought to be worth a try rather than spending on new.

Low speed resistor has probably burnt out on the main fan. Test resistance between pins 1 and 2 of the connector on the end of the wires emerging from the fan motor. You should see a small resistance, I suspect you'll see open-circuit. Repair is possible with a large external power resistor, see here: Mk.4 Golf/Bora radiator fan fix. | Volkswagen Mark IV Forum (uk-mkivs.net) or here https://www.briskoda.net/forums/topic/404143-radiator-fan-repair-courtesy-of-vortex-here-and-uk-mkiv-forum/

camshaft timing chain; slide rail - Octavia(OCT) [EUROPA 2013 year] (7zap.com)

A coolant gauge needle bouncing off the top end-stop would've been less ambiguous. It wouldn't have cleared/reset with cycling the ignition either.

There are designed-in valve reliefs on the pistons for the inlet valves from memory. Confirmed in third photo here: VOLKSWAGEN POLO 6R Piston W/ Connection Rod 1.2 Petrol 51kw CGPA 2016 | eBay

Yes; see section headed 1.9 R4 8v TDI PD 43-118kW on this page: List of Volkswagen Group diesel engines - Wikipedia Long list, yours being about a third of the way down the page.

I think it will fit, judging from the numbers here: Skoda Octavia - Specs of wheel sizes, tires, PCD, Offset and Rims - Wheel-Size.com

As it's only going to be a spare, I'd personally have no worries about 'using' it for another few years. After all, it's only likely to be used cautiously to get you home or to a tyre place to get the other one sorted.

I've no clue what the acceleration issue is, but no harm in measuring compressions.

Checking for residual pressure in the expansion tank when engine is stone cold is probably a much better test of whether HG repair is holding.

It looks like a horribly complex system to fault find, so maybe the more thought the better. Get that oil changed next though, and see what difference (if any) that makes to the oil temps.

See post by @silver1011 here for what looks like a picture from a manual of what's meant to be in there (and where to find it, in subsequent posts):

They stopped including those stickers some time recently, meanly. Couldn't tell you exactly when, but 2018 rings a faint bell. That list screenshot looks like part of a full listing obtained via a cooperative dealer or from erWin.

Is that aimed at the OP, or me?

Maybe the oil cooler would be a good thing to check for coolant blockage/flow. I assume there is one.

The coolant temperature gauge is 'tweaked' in software to read 90C over a 'generous' temperature range to soothe customers who might worry, so the real coolant temp may well be rather less. You could do with some sort of scan tool reading live data. That could show you coolant temperature as read by sensor/engine ECU before software sanitisation in the cluster. You really need to get thermostats back in there at some point though.

For future reference, it would be better to ask for such info in the Mk1 Fabia subforum, as your profile and engine code suggest that's what you have. Either in a relevant thread there, or by starting your own. Tagging onto this one risks confusion for future readers expecting mk2 Fabia info.

This page has all the 288 brake bits' part numbers: floating caliper brake; brake caliper housing; bra... - Fabia(FAB) [EUROPA 2004 year] (7zap.com)

It's good that your engine survived that. No thanks to this design decision:

The wheels will probably fit over them, but you'd need to change the wheel bearing housings as well as all the brake bits, as yours will be the type with integrated carriers. The calipers for 288mm discs would need the other type with bolt on carriers. See items 7 and 7A here: wishbone; wheel bearing housing; anti-roll bar - Fabia(FAB) [EUROPA 2004 year] (7zap.com)

You may want to fact-check that one.