Golf mk 5 sdi weired noise

put in some iridium spark plugs and change oil and filter

I would get a diagnostic check done on it as could be a number of things, is your engine management light on or does it come on at any point.

Check the VAG code. I had the same problem with my MK V 1.4 FSI. Let me guess when you rev it, it dusnt shake anymore?

It might be one of your cylinders are misfiring. And this might be faults with spark plugs, coil pack or the injector. You'll be lucky if it is the first two as they aren't much expensive to repair. It will cost you if it is the injectors.

the metal plate that connects the crankshaft to the torque converter ,its splitting around the bolt holes

What colour is this light.
The Golf mk4 sdi certainly should have brake pad wear sensors front and rear and the light on dash for this is orange with a similar symbol to what you describe.
The ABS light is orange with ABS printed on it
John

could be the compressor is loose
check all bolts are tight!

Chris I would get the coolant system pressure tested and it might show up the problem

fuel relay could be faulty. i think its number 30 or 167 in the fuse box under the driver side steering. it could also be the fuel pump or connector on the fuel pump under the black metal plate under your trunk carpet. you could try manually throwing in fuel into the intake to make sure its not your car's ecu or ignition system. if it starts and stays running it could be what took me a few months to discover after i had intermittent problems. there a small vacuum hose from the fifth injector on a 1997 mk3 gti (4 cylinder) that connects to the injector rail. i think its some kind of activation for the electronic injectors. my pipe was broken and i just cut it and my car hasnt been better since! i know this is an old question but i hope it helps someone out there!