welcome.

hi just a question, did the tick just start or has it been there for a while, it sounds too fast for a single cam lifter. it may pay to take the tappet cover off and check the rocker assembly as the rocker assembly it can pull threads and create rattles which would explain the fast rattle sound you have. your rattle noise is a bit loud and fast for a small nuisance rattle IMO.

if you are going to remove the front assembly take out the front drive shaft and check your unis and also go for a quick drive and see if the noise is still there. never know it might save you alot of work.
just a thought have you got any rocks in your tyres as they can make funny noises at times , try blowing them up to max and go for a drive , it might fly out

my 97 gems have velour seats and no electrics, not even an up or down button.

if it's black unburnt fuel then it's definatly an electrical problem. i had issues with dodgey maf and ended up making a lead that i could pin the maf with using a multimeter . just squash and cut up some electrical clips and some heat shrink , dosn't have to look much as long as you can pin the conectors . i think from memory there is a power wire 5v a ground wire and a signal wire . if your a mechanic you would know not to short out or put power on the wrong wire. black one to ground red one on the wires , do not put power on signal wire or you will be replacing the ecu. this was the only way i could check the maf properly and convince my self it was the problem. the signal wire should be steady on the reading not all over the place.

I like the open chisel idea, but with hindsight i'd buy a sacrificial cold chisel 12 to 18 inches long and grind it to about 2mm thicker than the slot you need to spread on the shaft and to the same width as the length of the slot. TIme spent on prep will be well.spent...

or use a screw driver

a long shot but check for air leaks on the inlet side, use a spray bottle with water in it and literally just spray it on all surfaces, it will squeal if you find one. the fuel pressure is low and if the motor was under load, it would be using more fuel so the pressure would be even less so defiantly an area of concern but usually with low pressure you just get sluggish performance. do you have an old timing light, if so check all the spark plugs are working and see if the miss is electrical . you said you changed the maf , if so put the old one back on and see if there is a difference. some more things to check.

i think they only go on in one spot, it's missing a spline, is the box centered

slow down a bit, first thing is go and look at the shafts , there's two of them , if you think its a balance issue and it wasn't there yesterday but is today then it would have thrown a weight off the shaft and you would be able to see where it came off. the next step is see if there is any movement in the uni joint , to really see this you need to remove at least one end to really see if there is any movement . also check that the pinions and the output shafts from the transfer box and the diffs are tight , no movement.
PS my guess is uni joints.

i had a similar issue , just drill the head off the screw and remove the tps . with the rest of the bolt hanging out use a pair of vise grip pliers to remove. i just clip them on and move it up and down in little movements, it will hopefully come loose. the theory is that it warms the screw and it will eventually come out , this can take 5 minutes of moving it up and down to loosen it, do not rush it or you will be drilling it out. every 5-minute job is one broken bolt away from a 3 day ordeal.

use to get a similar setup on old vw combies, we called them pop tops.

that's good, i have a front cover with a bad oil pump, i can see cracks in the retainer for the pump, the motor also seized. not sure whether the case is ok but i kept it just in case i or someone needs it.

the real question is are all the bits there, it looks like they are,

water will boil at 100dec to heat water above 100 dec you have to increase the pressure. the pressures that are mentioned are in the area of the temps i mentioned. you cannot have one without the other, we are delving into the area of latent heat to increase the pressures above boiling . operating temps are around 85 90 dec running temps , if you remove the cap at that temp the temperature will go from 90 dec to the flashing point or instantly boiling as it is the pressure that stops it from boiling. without the pressure the cooling system will not handle the temperatures. the only way to increase the pressure and not the temps is a cylinder leak of some description, either way it's not good, it's telling you there is something wrong.
PS the thermostat controls the pressure by controlling the temperature.

those pressures are a bit worrying as the thermostat is suppose to control the temp, at 1.4 bar that's max pressure for the system, the system should be around .8ish bar or so around 9psi is a good pressure to have. do you have temp readings or just pressure as the temps for that pressure would be around 118+ degrees. there is something wrong with the system, you are running around 20psi which is way over the top for the system

looked like a good day of fun wheeling around the bush.
good video.

thats interesting to hear from people that actually have EVs as i dont know anyone that owns one or a hybrid for that matter, only what i have read . the RFD that you speak of is what is going to happen with all EVs as someone has to pay for the roads and maintenance. the states in Aust started charging per km until someone pointed out that the states can't charge that sort of tax so it got scraped, now it's a federal issue so the states miss out on the tax , it will go to the federal gov and most likely cost more and be attached to CPI, so even dearer, dumb move in my opinion.as stated before if i only had to drive 100km from my house i would consider an EV or more likely a hybrid. i may not drive for a week but when i do it;s to tow something or drive hundreds of km's so not my cup of tea at the moment.

iv done this job on mine , the biggest issue i had was with the adjustment nut on the bottom ball joint., be careful that it dosn't wind in when you do up the nut , just holding the bottom of the balljoint dosn't stop the adjuster winding up and jamming on the housing. it took longer to loosen that bloody thing than it took to do the job, twice, and yes it leaks .

mine has an eka number and is Australian "97 gems "

do not use silicon anything unless its grease to help in assembly. use nitrile o rings , some recommend buying original o rings as they arnt that expensive. done properly they will last many years. do not over tighten them as you can crack the housing, just tighten and then loosen off half a turn for expansion!
PS if the screw is tight or corroded at the back of the screw you might have to drill the head of the screw and unwind the rest of the screw out the back of the retainer. you may have to buy a longer than usual drill bit to reach the screw.