BlueWagon

Maybe a grub screw that locks into those recesses on the shiney bit of the new one, so at right angles to the main body

Looks like the case. You may need to replace the hose to the bottom of the close up picture

Id suspect the master cylinder is at fault? Was it an aftermarket ebay special?? I have seen aftermarket calipers and cylinders do similar thing on Toyota's in the past. Jambed brakes. That said, why did you replace master cylinder? Maybe that is the underlying cause??

Really depends on how it started. If it was suddenly then maybe yes, do get it looked at sooner. If it was a gradual thing (likely and you only recently noticed it) its probably not a massive deal. Id certainly be checking trans and diff oils ASAP though. Sounds alot like a worn diff bit do get back with the answers to the questions about the nature of the noise

Describe the whine in more detail. Does it happen in every gear or is it engine speed related? Does it come and go if you take your foot off the accelerator and coast? What about during engine or foot braking? As suggested try turning the wheels a bit while its happening? Does the noise change?

Degraded battery or poor terminal connection Id sort that before doing the diagnostic work Might clear alot of the faults

Fair. Probably best to let the mechanic do it. Wouldn't you just let the mechanic buy what they need? That's how it normally works right? You don't buy anything if you aren't doing the job. Just take car to mechanic and they will get what they need based on their experience.

I reckon after 5 minutes Id have turned the engine off....if not just to save fuel and exhaust stink. Water pump or pump drive belt failure Thermostat failure These seem most likely and probably easy to check with a bit of fiddling.

CAT? Flexible coupling? Flange? muffler? DPF? Turbo??? I dunno man, maybe post a photo man, then we can have a look and a better guess man

Maybe just old oil from small leak burning off a now much hotter engine. Id suggest not stopping engine if turbo is hot. Make sure you keep it running for a bit for turbo to cool down before cutting off the oil supply.

Also, make sure your car is level when you check the oil. My block is sloping and it's a PITA to accurately check oil levels.

This is what I'd keep doing. Maybe need to try startingwith a fine screwdriver to open up gap and get the larger screwdriver and then chisel in. Need to spin and insert chisel at same time. Sometimes a ring spanner can be used to pull a bit if you pull it off square a bit. Eg pull the free end outwards quite alot. Try pulling and working bolt back and fourth at the same time. Or, if you can get a welder, weld a link of chain onto the bolt head and pull on that.

My Octavia did this once or twice i just turned key off and restarted. Seemed fine after that. Software glitch Maybe just needs a hard reset. So discount the battery for a while.

Is the relay clicking on and off while fan turning on and off? Id be thinking false reading of temp somewhere

Check this. But would probably run with ignition off if this were the case. Really need a wiring diagram to see where the power to call the fan for does come from. Maybe ecu??

Do you mean the radiator fan? Id think that and the oil pressure switch are unrelated.... Suggest looking at temp sensors for the fan fault. Maybe faulty ecu Maybe stuck fan relay Need more details. Eg does the fan cone on as soon as you turn the key on, or to start, or is the ac on (that will make fan run)

Ratchet with multiple flexible extensions and alot of fiddling from underneath would be my first try Maybe from above but have to remove bonnet so you can lie on top of the engine and reach down

Did it crank ok without jump starter? Suspect air in the fuel system and it bled out while you cranked on it. Maybe a slight leak somewhere letting air in and fuel to drain back or out. Was it sitting long before you drive it that day?

Maybe it was serviced in March and sat around for a month or two.... The just before bit needs to be verified as a date rather than an approximate time. Id just service it now

Not saying your part is complete garbage....but genuine part and ebay dont really go together.... Maybe genuine rip-off or aftermarket in a genuine box...

More details? Does it start as soon as you press even lightly on the clutch, or only when fully depressed? Does it disappear in any specific gear? Does it do it in neutral and in gear? Does it match engine speed, what about when rolling? Eg fast coasting at say 40 and engine at idle? Could be either of these. Need more details. Throw out bearing normally makes some noise if slight pressure on it, spigot bearing does when clutch actually disengage.

Which part? Id think that the rattling suggests a problem. Maybe fix rather than remove? Got a photo

Then fix cooling system, don't add more fuel by tuning for more power

True...but any remap will be injecting more fuel. Gonna get hotter not cooler, so remap only gonna make overheating worse.

Remap only going to make it worse. More power comes from more fuel being burned so more heat generated. Cannot make power without generating heat. Id agree, need an upgraded cooling package if you want to work it hard. Likely nothing wrong with current system other than its only designed for 150 HP.