stef123

The rattle at idle is from the crankshaft pulley, very common thing.

No it's only a cylinder head temp sensor not a coolant temp sensor so nothing will happen if it's left open like that

It should still power up when connected with jump leads. Are you sure the jump leads are connected to clean surfaces?

Hello abs welcome Tom!
First of all, the pictures and video are VERY helpful! For a first post and a newbie I think you have nailed if for getting a good response.
Anyway, it looks to me like the valve cover or rocker cover gasket as some know it could be the problem here.

No they only need copper washers when using hoses/calipers with banjo bolts.
On the mk3 they use a tapered/come shape fitting to seal them

I'm confused now.. Surely to get the backing plate off the hub/stub axle must be removed as it's sandwiched in the middle? As far as I know the hub and stub axle are a one piece assembly on the mk2, is that right? Unlike the mk1 where you could replace the bearing atleast!

I would strongly recommend you disconnect the negative terminal first!
As a spark I have seen many cases of arcing and faults where sparks and bangs are produced of short circuits... The last thing you want to do is be disconnecting that positive terminal and short circuit it to earth by accidentally touching your spanner on the body of the car!!
You will probably find you have welded your spanner to the car and also filled your pants with a smelly substance!