new owner of '02 S60, Timing mark help and more

Hey guys, I'm a new owner of a 2002 S60 2.4T AWD.

It look like the timing belt was never changed... I went to a local dealer, got a belt and I removed all the timing covers yesterday and tried lining up the marks like the instructions.. I found the mark on the bit between the pulley and vibration damper but I couldn't find a mark on the engine block/oil pump to line it up with.. it looked more like a protruding bit of metal crudely represented here /___| with no obvious marks on it and some nearby bolt, with the marks on the camshafts lined up the mark on the crankshaft is somewhere in the middle of that metal thing. the guides that I've seen dont show this part of the engine in enough detail and was wondering if anyone had any experience with this and its the reason why im making this post, but I will continue on with some other stuff.

I've noticed the engine is pinging at near half throttle and concerned the timing may be off a little? (belt stretched?) It may just be bad gas.. i usually run 93 octane in my other car and it never pings, but this car still has gas in it from the previous owner so i will have to find out later.

So anyway onto some other details about the car what i've learned so far and what I need to fix.

I got it around 2 weeks ago with 145k on it and a broken rear-diff and I paid $2500 for it...seemed like a deal at the time since it ran smooth and ac worked and was priced well below fair market value.

I bought the car broken rear differential (case cracked pinion gear shredded) and replaced it myself with a junk yard part I got for $350 shipped to my door... seems like a really nice car now that its driveable.. it does shift hard into drive sometimes but i've got ATF from the dealer and plan on doing a drain and fill soon, didnt notice any problems shifting from 2nd to 3rd though and all the gears shift smoothly (a lot better than my other car; 95 mitsubishi galant).


Another thing is the driver power seat work intermittently... anyone else ever experience this? I checked the fuses in the car and they're all fine.

I've probably put $1000 dollars into this car already and I'm concerned things will start failing and it will become a money pit... normally I wouldn't buy a car with so many miles and the previous owner kind of neglected it, but I hope to change that.

I've just ordered a bunch of other parts tonight that I'm going to replace... front sway bar links (theyre banging around), top engine torque bushing from ipd (its busted), fuel filter, spark plugs (volvo / Bosch ).. oe headlight wipers (theyre falling apart)

I'm also thinking to order two whole font control arms since the front wheels moved quite a bit when kicked, can also feel a lot of torque steer.

I would have thought twice about buying this car were I able to properly test drive it at speed, but it seemed like a much better car than what I currently own ( 140k on it and a lot of things just dont work) .

Hope someone can help me with some of these issues, or maybe share their experiences, thanks in advance.